French Onion Soup is essentially caramelised onion in soup form topped with cheesy bread. The French are genius!
Caramelising onions calls for patience, but it’s worth it. You’ll be rewarded with deeply golden, intensely sweet onions that forms an incredible flavour base for this French Onion Soup. For an effortless option, see how to caramelise onions in a slow cooker!
THE ICONIC FRENCH ONION SOUP!
French Onion Soup is probably one of the most epic soups in this whole wide world. And yet, the soup itself is made with very few core ingredients: butter, onions, flour and stock/broth.
The magic is in the caramelisation of the onions, cooked slowly for at least 40 minutes. And of course the crowning glory – the glorious melted cheese toast!! Because let’s face it – French Onion Soup without the cheesy toast is just onion soup. Meh!
CARAMELISED ONIONS – STOVE OR SLOW COOKER
The caramelised onions are the star of the soup (well, on par with the cheesy toast). Making caramelised onions the classic way on the stove takes upwards of 45 minutes for a giant mound like we use for French Onion Soup.
It’s not high-stress or high-energy effort. For most of the time, the onions are cooked over low heat so you just need to stir them every now and then.
It’s the sort of thing that’s good to make while pottering around the kitchen doing other things. My cast iron pot is 24 cm / 10″ wide and it was full to the brim with raw onions and took almost an hour to caramelise. If you have a wider base pot, it will be faster – probably closer to 45 minutes.
Though of course, if this all seems like too much effort for you…… introducing….
SLOW COOKER CARAMELIZED ONIONS!!!
Yes. You. Can!!!
I first learned of this from a reader then found this recipe on TheKitchn. Terrifically convenient and totally hands off, just throw the onions in, drizzle with butter or oil then leave on low for 10 hours.
This will get you 75% of the way there. The onions are browned a bit but lack the same intensity of flavour you get from caramelising on the stove.
So you do still need to cook the onions on the stove for 10 – 15 minutes to achieve the same true flavour. And while one may wonder what’s the point, there’s a big difference between cooking down onions for almost an hour on the stove vs 10 minutes.
Plus, no having to man-handle a gigantic mound of onions in a pot that’s too small (me, me!).
THE REST IS EASY!
Caramelised onions aside, the rest of the soup is effortless. Get all the tasty brown stuff off the bottom of the pot by deglazing it with a touch of wine. A touch of flour to thicken the soup every so slightly, a LOT of broth, and an optional sprig of thyme and bay leaves.
GOOD BEEF BROTH IS A MUST!
If you use store bought, which I often do, use a good quality beef broth/stock. I personally do not recommend any of the mainstream brands sold in Australian supermarkets. I use Maggie Beer and Moredough from Harris Farms (I stock up when it’s on sale!), or private labels from butchers.
If you can’t get good quality beef broth, use chicken or vegetable instead. I find that the quality of those by mainstream brands is much better than the beef stock. The beef is fine to use in things like gravy and stews, but not when it’s a key ingredient like in this recipe.
DON’T HAVE OVEN-PROOF SOUP BOWLS?
Neither do I! Can’t justify the storage for ONE soup that calls for it. Sure, it looks thoroughly dramatic to be served a piping hot bowl from the oven with the entire surface covered in bubbling cheese (and a piece of bread under there somewhere).
But actually, I prefer making grilled cheese separately and popping them in the bowl because the bread isn’t as soggy from absorbing the soup by the time it gets to the table.
And lastly, a little tip – try the grilled cheese with your very own homemade Artisan bread. It is mind blowingly easy and has been wildly popular with readers since the day I shared it! – Nagi x
FRENCH ONION SOUP RECIPE
WATCH HOW TO MAKE IT
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French Onion Soup
Ingredients
- 100 g / 3.5oz unsalted butter
- 1.25 kg / 2.5 lb brown / yellow onions , peeled, halved, thinly sliced top to bottom (Note 1)
- 3/4 cup (185ml) dry white wine , optional (Note 2)
- 2 tbsp flour , plain / all purpose
- 1.5 litres / 6 cups / 1.5 quarts good quality beef broth./stock OR chicken , low sodium/salt reduced (Note 3)
- 2 dried bay leaves (or 3 fresh) (optional)
- 3 sprigs fresh thyme (optional)
- Salt and pepper
Cheesy Toast
- 6 – 8 slices French baguette or other softish bread (Note 4)
- 100 g / 3.5 oz gruyere or mozzarella cheese, or other melting cheese of choice
- Fresh parsley or thyme leaves , for garnish (optional)
Instructions
Caramelise Onions (See Notes for SLOW COOKER option)
- Melt butter in a heavy based casserole pot over medium heat. When it starts to foam, add onions and stir to coat in butter.
- 30 min on medium low: Turn heat down to medium low. Cook for 30 minutes stirring every few minutes, until the onions have softened and are semi transparent.
- Salt, 20 min on medium high: Turn heat up to medium or medium high. Add salt, and cook for a further 20 – 30 minutes, stirring more regularly, until onions are deep golden and sweet.
Make Soup:
- Deglaze: Add wine, then simmer rapidly for 2 minutes until mostly evaporated, stirring to scrape the bottom of the pot.
- Flour: Sprinkle flour over the onion and cook for 1 minute.
- Add broth & herbs: Add broth, thyme and bay leaves.
- Simmer: Cover, lower heat so it’s simmering gently then simmer for 30 minutes.
- Serve: Season to taste with salt and pepper. Ladle into bowls. Top with 1 or 2 slices of cheesy toast.
Cheese Toast:
- Preheat grill / broiler to high.Toast each side of bread until light golden.
- Top bread with cheese, then grill until melted and some brown spots appear.
Recipe Notes:
Nutrition Information:
COMPLETE YOUR FRENCH MENU!
Pan Fried Fish with Brown Butter Lemon Sauce (Totally French! Poisson meunière)
Garden salad with French Vinaigrette
Chocolate Mousse (classic French)
LIFE OF DOZER
I KNEW I’d find a use for those onion goggles one day! 😂 (I don’t need them, I wear contacts so I’m onion-proof. Gimme all the onions to chop!)
French Onion Soup recipe originally published in September 2016 as part of a Chasseur cast iron cookware giveaway. Since this time, the recipe has evolved (adding more flavourings – wine, thyme and bay leaves) so new photos, words and recipe video added!
I would make your pork carnitas!!!
USA
Hi Nagi, I’m in Australia (Sydney) and although it’s warming up, I think the first thing to cook would be Manu’s Boeuf bourguignon. His book is one of my favourites and most used, and I think winning one of these Chasseur beauties could be the special occasion I have been waiting to make this for! ?
Hi. To celebrate and honour French cooking, I’d make French beef stew (pot-au-feu). It would be a feast. I live in Sydney, Australia.
To celebrate and honour French cooking, I’d make French beef stew (pot-au-feu). It would be a feast. I live in Sydney, Australia.
Victoria, Australia. A delicous beef curry or French onion soup ?
Kylie
From NSW, Australia.. In the shallow casserole pot, the first thing I’d try is a slow cooked pork belly with fennel, onion, and star anise/spice broth. We do this now in a standard roasting try but have been dying to try it in a proper dutch/french shallow pot because the flavours these create are fantastic!
Hi Nagi … Brisbane, Australia. I would give a Mexican Chilli recipe with cheesy cornbread dumplings that you put on the top as you do the last step of the recipe. Thanks.
Hi Nagi,
I ❤️ Your blog and am working my way through some of your recipes. Home made teriyaki marinade made tonight- smells delicious! I’m from Victoria, Australia. If I won I’d cook yummy homemade baked beans with chorizo In the ‘French oven’
Hi Nagi I’m in Western Australia. I would make your Beef Rendang with h deleted copy’s meltingly soft beef cheeks. Favourite recipe ever❤️
Rendang…..so good it makes me want to cry ?
Damn auto correct. Beef Cheeks*
USA
Your French Onion Soup recipe looks amazing, so that’s going to be the 1st thing I make when I win! 😉
Hi Nagi
I’m from Sydney, Australia. Would love to cook some beef cheeks in Pedro Ximenez sauce. Had it once at a restaurant and the sticky sauce was divine! Since then I’ve always wanted to try making it 🙂
Ps love your blog. Great simple but delicious recipes to whip up post work (e.g. now). Keep it up!
Steph xx
Movida!!!! I can’t believe it’s closed….?
I am in Oz, Adelaide. And as i sit in the darkness of a total state power outage, I am thinking of a beautiful, rich ragout
OMG I just saw it on the news!!! But does it feel romantic with loads of candles around?? Or is it just plain annoying ?
Hi Nagi
From Act Australia. I love meat so perhaps I’d try lamb shanks 🙂
Thanks
Hello from Australia, this pot would get no rest in my house but the first thing i would make is Sticky maple and bourbon pork ribs. Yum
Hello from Los Angeles, US!
If I hat one of those beauties the first thing I would cook would probably be a chili. Then I might have to try that onion soup of yours, sounds delish!!
Hi from Australia , I would make a Beef Casserole
Hello from the U.S. I hope I win because the first thing I would make would be a hearty beef stew! ?
hello from the USA!
the first thing I would make would be roasted duck to prep for thanksgiving! thanks for the giveaway! I can’t wait to try this French onion soup 🙂
I live in the US and I’d love to make a Baked Mac & Cheese or this French Onion Soup! Bring on the melty cheesy goodness!
I’m in Texas, USA as its getting cold I would make a soup probably pumpkin!!