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’m from San Francisco, California. My first dish would be osso bucco, followed by beef stew,
I am from the US and I would make a lamb stew.
LOVE your site, Nagi!! – so many fabulous dishes have graced our table thanks to you! Here in the US, in Connecticut, fall is approaching so I am getting ready to come back inside from the grill and start heating up the kitchen with more of your wonderful recipes. If I am lucky enough to win I will make one of our favorites – jambalaya! I haven’t seen it as one of your recipes but I think this would be just your style – simple and delicious!! It would be SO GOOD in a beautiful Chasseur cast iron casserole pot (aka Dutch Oven aka French Oven!), especially in Dutch Egg Blue! Keep feeding us with goodness!
Hi Nagi! I’m from Montréal (Québec, Canada), and you can be sure that if I win, the first thing I’m going to cook is this French Onion Soup that looks so yummy! I’m pretty sure it’s going to be awesome, just like every other recipes that I tried from your blog!
I’m from San Francisco, USA.
Coq au Vin is on my list and the delicious looking recipe for the onion soup (my favorite.)
Thanks so much for the very generous give-away!
Love your site and recipes especially slow cooking…
I brought frozen pork and beef carnitas for our week
long canoe trip this summer. A big hit.
If i won the pots I would continue exploring starting with your
lamb shanks.
OMG, it would just have to be Lamb Henry, a classic dish for another classy dish.
Hi Nagi,
Faithful reader here. I live in North Carolina, US. I’d love to have one of those beautiful French casseroles to make a Bolognese.
I’m in the USA and I’ve been wanting to make a braised chicken thigh with shio koji. I’ve been putting off making it bc I don’t have a proper Dutch (or French 😉 ) oven.
America –
The first thing I would make of course would be the French onion soup…..it has been one of my favorite soups since I was a teenage (that’s a LONG time ago), and living in the Midwest there are not very many places that serve it.
I am so happy that I found you blog!! I’ve made several of your recipes and they have all been major hits!
Nagi, that French Onion Soup looked soooooo good in the email that I want some NOW! I’m so glad I can use chicken stock, since I have a lot of home made stock in the freezer, and will be trying this if I can find brown onions somewhere.
I’m in Canada and would likely make Beef Bourguignon as the first meal.
Am looking forward to the Coq au Vin recipe.
Leslie
PS What are called Brown Onions in Australia are called Yellow Onions in Canada. They are easy to find!
I’m from Newport, PA, USA and I’d make a pot of Guiness Beef Stew or your Chorizo Risotto! YUM!
I am from the US, Tennessee, and I would actually give this French onion soup a try.
I love the cast iron cookware, have one that I use all the time but would love one for the cottage!! I would make your lamb shanks for a cool Thanksgiving Feast.
Hi Nagi! I’m from the U.S. I would love to win a french cast iron casserole pot. They are just gorgeous! I would use it to make chili and rump roast with gravy along with countless other things! Thanks so much for the awesome giveaway! 🙂
Hi I live in the US but moved from the uk 3 years ago. The first thing I would make is what my mum calls ‘chicken chuck it in’ basically a comforting chicken stew that reminds me of home. A whole chopped up chicken, carrots, spuds, stock and that’s about it. My mum would make it a lot when the cold nights set in…so it reminds me of her and even though she’s thousands of miles away it’s like she’s eating dinner with me and her grandkids!
I am in the US. I would make a big batch of chili followed by Osso Bucco.
First of all, I want to thank you for everything!
All recipes I made from your website are always a delish!
My son and my husband are always happy and confident when I say: I’m trying a new recipe from Nagi tonight!
I’m Canadian and I would absolutly try your French Onion Soup as first recipe if I win the Chasseur Cast Iron casserole pot. As fall is right next door for us, it would be the perfect timing to cook with this new kitchen tool each week-end!
WE would most likely make the Lamb shanks first, along with the Onion soup, which is really tasty. We’ve always wanted a set of these pots but find them very expensive in the shops, keeping our eyes open each time we go to estate sales, hopefully will get lucky one day or maybe win one from this contest.
We live north of Seattle Wa.
Ahh they’re so beautiful! I’m from Wales (UK, not NSW! 🙂 ) I really want to try and make bbq beef brisket, apparently these are the way to do it!