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!
Hi New Jersey, USA checking in here! Love these pots! Would make pasta sauce with short ribs. Just canned over 500lbs of jersey plum tomatoes! Next would be the delicious French onion soup! Here’s hoping to being lucky!
Hiii there! I am Alissa, currently living in France. HAPPY FRENCH WEEK :D. With the fall weather coming in I’d surely be making stews and soups, but the very first thing I’d make is Bread!!! I keep seeing posts about making bread in a dutch/french oven and been really envying those folks and wanting to try it out.
Thanks for all the gorgeous inspiration!
I live in Idaho, US. I am in soup mode so the next recipe I want to make is your ham, potato & corn chowder.
Hi. I ‘m from Athens Greece. I would love to make braised beef or chicken but i would really love to try the french onion soup. I looks delicious.
Hi, this is Yi from U.S.
I am a big fan of stews and the first thing I’d like to make with this Dutch oven is boeuf bourguignon.
Thanks for hosting the giveaway!
Hi Nagi!
I live Toronto, Canada. The first thing I would like to cook using Chasseur is Paella.(Alloz con Pollo). It’s one of my husband favorite dish.
Hi Nagi, this is Lokness from Los Angeles, USA. I have been thinking about making Korean braised short ribs! That beautiful dutch oven would make a perfect use! 😀
By the way, French onion soup is one of my favorites! Can’t believe I have never made it! I will try it as soon as the weather starts to cool off.
C’est Bon! I adore French Onion Soup, and the above recipe looks perfectly fabulous. Although I will be making the recipe tomorrow , it will be the first meal I prepare in my new Chasseur cast iron pots. Not to mention they’re gorgeous too…
I’m a Rhode Island native, living in the USA.
Hi , i’m Polish living in the UK. I would love to own this beautiful pot. First meal I would cook in it would be Fasolka po Bretonsku. Which is Polish dinner inspired by British cuisine. My English husband loves it ☺
Hi fron NSW Australia. I can already smell a beautiful lamb casserole, or maybe it’s my nan’s favourite soup!
I would love to cook a paella. With a crisp rice base, juicy meat, and thick tomato-y rice centre.
Yum!
What is it about cooking slow and leisurely that makes such a lovely experience?!
?
Hi Nagi! Joey, Gerber and I love your stuff. Please pick us!
Jennifer from Canada and the first thing I would cook in those beautiful ovens would be a Filipino beef oxtail and peanut stew called Kare Kare.
I can not wait to make your french onion soup recipe in this pot
Hi I’m from England and the first thing I would cook is a chinese roast pork shoulder to go well with dinner and lunch. Plus being a student and all cooking that much will sort me out for the week on lunches.
Bonjour Nagi, In my dreams I live in Provence with the lilac and sunflowers, but in reality, it’s Sydney. First thing I’d make would be potato and leek soup, with melty Gruyere toast. Love your work!!!
New Zealand – Hungarian Goulash – haven’t had it for about 20 years!
After recently watching the movie Julia and Julia for the first time, I’ve been dying to slow cook a beautiful beef bourguignon using Julia Child’s exact recipe. This gorgeous duck blue Chasseur Cast Iron Casserole Pot would be perfect. I would so love to own one! Thank you, I’m in Perth WA 🙂
Catherine from Australia here. I’d love to cook my husband’s amazing beef rendang in these! Along with loads of your incredible dishes. Yuuuuum.
Hi! I’m from Vic, Australia. The first thing I’d cook is the French onion soup!!!! I have a cold right now and some soup would go down so well! (I would have said the Guiness stew but I’ve made that already and can confirm that it is damn delicious!!! ?)
Kim