I love a good roast lamb (proof). Here’s my classic recipe for lamb leg, rubbed with garlic and rosemary, served with gravy, peas, carrots and crispy roast potatoes (duck fat or classic). I hope you love it as much as I do!
The only thing you need to know for perfect roast lamb leg
I have a lot to say about roasting any kind of meat. Especially Australia’s favourite roast – the great lamb leg. But there’s really only one thing you need to know to make perfect roast lamb leg, every single time:
GET A MEAT THERMOMETER!!
It’s the only way you can take the guesswork out of cooking lamb leg so it’s perfect blushing pink and ridiculously juicy inside. Because – and here’s something Aussies don’t like to talk about – lamb leg is actually very lean so if it’s not pink, it’s dry. Full stop, end of story!
My meat thermometer – For most of my adult life, I was using a $5 thermometer I got on Ebay which never failed me. A few years ago I finally decided it was time to invest in a real one so I got a Thermapen which is pretty well regarded as the best (my thoughts here). Even if you can’t invest in a Thermapen – it’s the 21st century, and even cheap tech isn’t so bad. Invest in a $5 meat thermometer. That’s a lot cheaper than a wasted, overcooked lamb leg!
OK, I do have a few more “how to make the perfect roast lamb leg” tips!
Garlic rosemary rub – classic lamb flavours.
Start on high to get the colour going then lower heat.
Roast on a bed of garlic (or onion).
Make the gravy using the pan drippings. Roast lamb gravy is better than every other cut of meat – beef, chicken, pork, none of them compare!
What you need for roast lamb leg
Starting with the hero ingredient – the lamb leg! Get the best you can afford – yes, meat is like wine, the more you pay, the better the quality. Quality of life of the animal also comes into play there.
All that red ink you see is perfectly safe to eat and actually, you only see it on better quality lamb. You don’t typically see it on supermarket lamb.
Cut bone – Some (most?) butchers and almost all supermarkets sell lamb leg with the shank (bone) cut. Either fully cut off or partially cut so it folds. This is simply for practical reasons – shelf storage and packing space. For grandness, I like the bone in tact. But it doesn’t matter ,it’s purely a visual decision!
Rub for roast lamb leg
Here’s what you need for the rub: rosemary, garlic, olive oil, salt and pepper. Use fresh rosemary – dried is not the same!
Roast lamb gravy
All you need for gravy is flour for thickening and beef stock/broth for the liquid. You shouldn’t need extra salt for the gravy. I find the salt on the lamb that ends up in the pan drippings plus the salt in the beef stock is enough. But taste and add more if you want!
Why beef rather than lamb stock? Well, there’s a reason lamb stock is not typically sold at grocery stores! It’s just very…lamby. 🙂 Beef has a cleaner flavour. It doesn’t make the gravy taste beefy at all because there is so much lamb flavour from the drippings.
Why not chicken stock? It works fine but the gravy colour is paler. I like my gravy for roast lamb leg to be a really deep brown colour!
How to make roast lamb leg
Rub with rosemary and garlic, roast in a hot oven to get the colour going then continue at a lower temperature for 1 hour or until the internal temperature is 53°C/127°F (for blushing pink perfection). Rest for 20 minutes before carving. It will still be very warm even after 1 hour – enough time to make duck fat potatoes!
The lamb leg pictured is a 2.75 kg lamb leg which is about the average size you get from good butchers. Supermarket lamb legs tend to be a little larger from slightly older animals which makes the meat a little less tender and a little stronger “lamby” flavour. Albeit, as you’d expect, cheaper than from butchers.
Make rub – Mix oil, garlic and rosemary in a bowl.
Rub then sprinkle – Slather the rub all over the lamb, then sprinkle the salt and pepper all over. It’s better to do it this way for more even dispersion of salt – if you put it in the oil, it doesn’t spread quite as evenly because it pools in the bottom of the bowl.
I do this rubbing step in the roasting pan – why dirty a cutting board??
Garlic bed – Place cut garlic and rosemary under the lamb.
Hot oven 20 minutes – Roast for 20 minutes in a hot 240°C/475°F (220°C fan) oven. This will get the colour going on the lamb. It’s tempting to go longer to get even more colour on it but I find if you go beyond 20 minutes you end up with too much overcooked meat “ring” on the outer edges of the lamb.
1 hour lower oven – Reduce heat to 200°C / 400°F (180°C fan) and roast for a further 1 hour or until the internal temperature of the lamb is 53°C/127°F for blushing pink perfection.
Check the internal temperature at the 45 minute mark. Never rely on a recipe cook time for roast meat, use your thermometer! So many variables can affect the exact roasting time, from oven strength to pan heat distribution, the shape of the lamb leg and how cold the meat is right in the middle.
See below for more information on lamb doneness and different size lambs.
Rest 20 minutes – Rest the lamb for 20 minutes before carving. During this resting stage, the lamb finishes cooking and the internal temperature will rise to 62°C/144°F which is perfect medium rare for lamb.
Also during resting, the lamb juices get re-absorbed by the meat fibres so when you cut into the meat, the juices remain in the meat and eventually end up in your mouth. If you do not rest the meat then the meat juices leak out everywhere when you start carving the lamb.
Internal temperature of roast lamb leg
No credible restaurant would ever serve lamb leg at anything over than medium rare! But I do know some people like their lamb done a little more, so here are the internal temperatures for lamb leg at different levels of doneness.
Take the lamb out when it hits the “temperature out of oven”. After resting for 20 minutes it will rise to your target level of doneness.
TIP: Take the lamb out early!!!
This is one of the most common mistakes people make when roasting lamb. If you want medium rare lamb and you take the lamb leg out of the oven when it hits 62°C/144°F (which is the medium rare target temperature), it will rise to 73°C/163°F once rested which is well done – no hint of pink at all! This occurs because the lamb continues to cook after you take it out of the oven due to residual heat. It’s called carry-over cooking.
So if you want medium rare, perfectly pink lamb leg, you need to take it out of the oven once the internal temperature reaches 53°C/127°F. At this temperature, the lamb is rare.
But when you rest the lamb for 20 minutes, it will continue to cook and the internal temperature will rise by 9°C/17°F to 62°C/144°F. This temperature is medium rare, the optimum doneness for lamb leg so it’s beautifully juicy. Any more and the lamb meat is drier than ideal, because lamb leg is a lean meat.
How to make gravy for roast lamb leg
Gravy for lamb leg is made using the pan drippings after roasting the lamb. “Drippings” simply refers to the fat and meat juices left in the roasting pan after roasting the meat and it’s our express, free path to a killer gravy.
Heat drippings & cook flour – Once you take the lamb out of the roasting pan, put it straight on the stove to heat the fat. Add flour and stir it for 1 minute to cook it off – it will kind of be like a paste.
Pour in the beef stock, stirring as you go to help dissolve the flour.
Smush the garlic with a potato masher or even a smooth to help release the beautiful caramelised garlic flesh into the gravy.
Strain – Then just simmer for a few minutes until the gravy thickens to your taste then strain into a bowl, pressing the gravy liquid out of the garlic heads. Then pour into a jug to serve!
And that, my friends, is everything you need to know to be the king (or queen) of roast lamb leg from this day forth. The precision by which you roast your lamb to blushing pink perfection will be admired. Your gravy will be whispered about in your circles – the flavour!!! It’s incredible!
Just smile sedately, sit back and bask in the praise. There is no need to reveal your recipe source. 😎
The lamb leg in this post is pictured with duck fat potatoes (the best crispy potatoes in the world!) with peas and steamed carrots tossed with a little butter and parsley. If you don’t have duck fat, make my classic crunchy roast potatoes instead. They are still way crunchier than your usual way of making them.
Go forth and enjoy your new lamb-alicious world! If you’ve got your own lamb leg secrets, sharing in the comments below – readers love hearing what you have to say. – Nagi x
Watch how to make it
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Roast Lamb Leg with Gravy
Ingredients
- 2.75 – 3 kg / 5.5 – 6 lb lamb leg , bone-in (Note 1)
- 1 1/2 tsp cooking salt
- 1/2 tsp black pepper
Rub
- 1 1/2 tbsp fresh rosemary leaves , finely chopped
- 3 garlic cloves , finely minced
- 2 tbsp olive oil
Base
- 2 whole heads of garlic , halved horizontally (Note 2)
- Few sprigs rosemary (optional)
Gravy
- 4 tbsp flour , plain/all purpose
- 2 1/2 cups beef broth / stock , low sodium (Note 3)
Instructions
- Take lamb out of fridge at least 1 hour before roasting. (Note 4)
- Preheat oven to 240°C/475°F (220°C fan) with oven shelf in the middle.
- Rub – Mix rosemary, garlic and olive oil.
- Prepare lamb – Place lamb leg in a roasting pan. Coat with the rub using your hands, the sprinkle with the salt and pepper. Place garlic and rosemary sprigs underneath the lamb, garlic cut face up.
- Roast lamb leg for 20 minutes. Turn the oven down to 200°C/400°F (180°C fan) and roast for a further 1 hour or until the internal temperature reaches 53°C/127°F for medium rare (Note 5 other doneness). Check first at 45 minutes – everyone's oven is different!
- Rest – Remove lamb from oven. Transfer lamb to plate, loosely cover with foil and rest for 20 minutes to 1 hour (it will still be warm enough for serving!). The internal temperature will rise to 62°C/144°F (medium rare). Make gravy while lamb is resting – below.
- Serve lamb with gravy, duck fat or classic crunchy roast potatoes, peas and steamed carrots tossed with butter and parsley.
Gravy for roast lamb leg
- Drippings in pan – Discard rosemary sprigs. You should have around 4 – 5 tbsp of fat (drippings). If less, add butter. If much more, discard a bit.
- Add flour – Place roasting pan on stove over medium heat. When the fat starts to bubble, then add flour. Mix flour in and cook for 1 minute.
- Stock – Pour in half the beef stock and mix to dissolve sludge in, then add remaining beef stock and mix.
- Garlic squidging – Use a potato masher (if you're really keen like me) to mush the garlic to squeeze out the flavour (also helps flour caught in garlic to dissolve).
- Taste – Check salt and pepper (I don't add more).
- Thicken – Simmer for a couple of minutes, stirring, until it starts to thicken. Take it off the stove BEFORE the gravy is the thickness you want because it will keep thickening.
- Strain into a bowl, mushing garlic to squeeze all the liquid out. Then pour into gravy jug and serve with lamb!
Recipe Notes:
1. Lamb leg – Recipe is based on a whole lamb leg. See roasting time table above for different lamb sizes. Sometimes the bone sticking out is removed, sometimes it is partially cut so it folds inwards. It doesn’t matter either way, but just ensure the bone inside the meat is not removed. (If it is, you have a butterflied lamb leg – use this recipe instead).
Boneless lamb – I love making Greek butterflied lamb leg. If yours is rolled and tied, you could make this recipe but the meat is not quite as juicy because it’s been cut to remove the bone so there’s more escape roots for meat juices! If you can, unroll the lamb to do the rub then roll it back up and tie again (excellent flavour infusion!). Also, cook time likely a bit shorter. I’d do the 20 minute high temp blast, lower oven then check at 40 minute mark.
2. Garlic base – Elevates the lamb slightly so it cooks more evenly and allows the fat to drip over the garlic so the flavour infuses into the drippings that then forms the base of the gravy. Place garlic cut side up so the flavour infuses into the flesh of the lamb.
It is not garlicky at all because when garlic roasts, it becomes sweet and caramelised. It is my big secret for making a killer gravy for roast lamb! You can use 1 onion, quarters (skin on) instead of or in addition to garlic.
3. Gravy for lamb is best made with beef stock/broth because it has a deeper flavour and makes the gravy a beautiful dark brown colour. Store bought is fine, though homemade makes it ultra restaurant-worthy! If you cannot consume beef for religious or health reasons, then chicken broth can be substituted.
4. De-chilling lamb will make it cook more evenly. Cold lamb leg = overcooked on the outside by the time the inside is cooked.
5. Internal temperature of cooked lamb leg:
I highly recommend getting a meat thermometer for accuracy – only guaranteed way to get juicy lamb every time!
6. Holding – The lamb leg will stay warm for up to 1 hour, enough time to make duck fat or classic crunchy roast potatoes! The inside of the lamb is still warm even after 3 hours.
7. Servings: A 2.5 kg/5 lb lamb serves 6 very generously and 8 comfortably. After taking into account the bone (500g/1lb) and meat juices lost during roasting, you should end up with around 1.7kg meat after cooking which is around 280g for 6 people (generous!) or 200g for 8 people. If you slice lamb thinly it will go further!
8. Nutrition per serving, assuming 8 servings and that all the gravy is consumed.Nutrition Information:
Originally published October 2016. I have been very neglectful not updating one of my favourite recipes with sparkling new photos and a recipe video!
I told you – I LOVE roast lamb! See?
Life of Dozer
Original photo from when I first published this recipe in 2016 still holds true, so no need to update:
DOZER. Don’t breathe your stinky dog breath over my friends while they eat!
So delicious!
We had this tonight with your garlic rice and sauteed green beans.
https://salesdock.info/garlic-rice/%3C/a%3E%3C/p%3E
https://salesdock.info/garlic-sauteed-green-beans/%3C/a%3E%3C/p%3E
I can’t cook. It’s a standard joke. Just made this lamb for my wife for our 25th anniversary. It turned out beyond perfect. Thankyou so much!
I made this today, fantastic.
Love, love, love your recipes. You have your own heading in Pinterest for me. Never had a failure yet. Thank you from over the Ditch. Barbie Heasley
Would it be okay to cook this in a Dutch oven (without the lid)?
Hi Nagi, thank you for sharing your lamb recipe! I made roast lamb for the first time and it was the best lamb I have ever tasted! Lamb was full of flavour and so succulent and the gravy was magnificent!
I have never been good at roasting a leg of lamb till I found this absolutely fail safe recipe. Perfect lamb every time.
Made this tonight for friends of mine who are currently doing a Reno and cooking out of their kitchen. This roast so hit to spot. Bringing the lamb to room temperature before cooking meant it cooked beautifully. I rested for an hour and it was so juicy. That gravy was amazing! Thank you Nagi for another crowd pleasing dish
Hi Ellen, how long did you leave your cut of lamb out? I’ve left mine out for 1.5 hours and it still feels cool to the touch, but I’m a bit worried I’ve left it out for a bit too long as it had a slight smell to it, even though it’s still within the best before by 5 days!
This roast lamb is the best. I didn’t believe it would stay warm for an hour while I did the potatoes, but it did!
Friend’s over for Sunday lunch.
Apparently, I set the bar too high 🙂
My lovliest moment was when the male said, ‘So, tell me how did you do those roast potatoes???’ Ha, ha.
I did the non ‘luxe’ version using peanut oil
i knew he was a foodie to notice so now he has this website and his friends are going to love him even more.
Thank you Nagi, you’re amazing as is Nigella and semolina xx
Oh yea Nagi, I got MOTH tonight.
He’s always claimed he’s king of cooking roast leg of lamb BUT he had to admit defeat.
This recipe is just the best, so full of amazing flavours and not losing the taste of the lovely lamb.
He has said to me tonight at least 4 times, WOW, that was the best roast leg of lamb.
I’m absolutely fist-pumping myself.
Brisbane Lions are in the G/final, all we need is Brisbane Broncos to make it a perfect Saturday.
You go girl!
I came here looking for comments on people who have had success. I saw your comment and just had to reply. I’m American but my BF is from Perth, Australia. Roasted Lamb is one of those dishes that reminds him of home. This gives me hope that this recipe will do just that!
Side note while he is a Carlton fan, I am a Lions 🦁 fan! I hope to see the Pie’s go home crying. 😂
Reading all the comments. So funny how everyone who felt like an eg sandwich is now roasting lamb. Hahahaha. Nice recipe. I always put several deep slits in my lamb and place slithers of garlic and the tips of rosemary shoots in them as well as place in pan. Roasting the lamb over the top of the roast potatoes lifts them to another level. And why not have carrots in there as well. I must admit though, I much prefer mint jelly or mint sauce with my roast lamb. Gravy is good. But I thicken my sauce with butter and never use flour. Very yum recipe Nagi
Lamb is the delicious and versatile. Have you ever tried Narsai David’s marinade? It uses pomegranate juice, onion, garlic, basil and red wine that provides a delightful brown glaze and infused flavor. It’s terrific for rack of lamb, grilled boneless leg of lamb, and a cannon of lamb.
Tried this yesterday but meat was a bit tough. Should I cook it under foil?
Hi there nagi, I’m planning to make this for our anniversary next week. Can I sub the leg of lamb with individual portion lamb shanks?
Look, i haven’t ever left a review although i read them all the time. i should have started with the lamb shawarma, which i made at home for 2 months straight until i adapted it as a special in the small restaurant i work in. This roast, like the shawarma, was over the top delish and the gravy was STUPID. i did the potatoes with bear fat(live in Montana) and some carrots and parsnips(baked with honey, butter, and cumin). Insanely good. Made sandwiches with some of the leftovers, and mini potpies with the rest. Thanks for yet another amazing recipe!!!!!
Nagi I made this yesterday Easter Sunday in Pensacola,Florida. Did exactly as you suggested and it turned out perfect. I have not made gravy for years now being lazy and using store bought in a jar, but decided the lamb needed the real thing. I had all the ingredients and tools magic using a potato masher to get all the juices. Many thanks from a former Northern Beaches girl.
It’s Easter today and I made your roast lamb leg recipe – it turned out perfect! Super easy and delicious. Meat thermometer really helped, definitely use one because even though Nagi’s time guide is reliable, my oven runs hot so I needed to roast for 10 less minutes. Thank you Nagi! Another winning recipe
Hi,
Lamb in the oven now,but for future reference if I want less gravy do I just add less flour and stock( taking out a bit of fat).There’s only 2 of us and a jugful is too much
Thanks
I chose this recipe to cook for Easter today and this certainly did not disappoint. Made it with the gravy suggested and it was worth the effort. The result was a tender leg of lamb that the whole family enjoyed, thanks Nagi ☺️
I am busy making this now for our Easter Sunday Supper and it’s my son’s 16th birthday. So holding thumbs I get the Super Mum medal. (South Africa)