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 live in the USA and the first thing I would make would be a rich beef stew with extra potatoes 🙂 I have been craving some lately! These pans are beautiful and the soup is going on my fall must make list!
Hi! I would love an opportunity to own such a beautiful set of cookware ? I live in the US, and if I owned it, I would make filet mignon in a mushroom wine sauce. ?
Hi Nagi! I love your comments, oblivious love of cooking, and every recipe I’ve tried so far! I have only made French Onion Soup twice before, and was not very impressed. I don’t have a heavy enough pot to really let flavours meld enough. I’ve looked at the dutch ovens, le creuset, etc, but they are sooooo expensive. It would be great to win either one of these pots.
The first thing I would want to cook is a pork shoulder for your pulled pork carnitas! I drool just thinking of the crunchy-sweet pork topped with a tangy cabbage slaw on a big soft bun. Yumm!
Omg this looks so yummy! I live in the U S A! So after I make a huge pot of Brunswick stew then I’d make this onion soup! ??????????
I live in Oregon in the (Pacific Northwest) USA. What a beautiful meal you’ve made! My favorite dishes are one-pot recipes and my favorite cooking pot is a dutch oven — they’re simply the best for long, slow braises and stews. It’s tough to choose, but I think the first thing I’d make is Irish Beef & Guinness Stew.
Cheers!
Hi Nagi,
I live in York Pennsylvania, USA and the first thing I would make in the Casserole pot would be a good, hearty beef stew. Fall is fast approaching here in the US and I can think of nothing better on a cool evening for dinner.
I live in Finland, city of Espoo. Pan bread or onion soup, so the Chasseur Dutch oven would be my choice.
Hi Nagi
I’m from the United Kingdom, and the first thing I would cook would be a slow-cooked, minted lamb hotpot with a healthy dollop of creamy mashed potato on the side. If it goes particularly well then I could send you the recipe if you would like!
I would really, really love one of the Chasseur pots. I live in Ontario, Canada.
Pick me, please.
Hi Nagi,
I’m based out of the US (San Diego, CA). Those French Ovens are such a dream. I would definitely make a braised short rib ragu or my Thai chicken curry with kabocha pumpkin. Perfect for Fall! Thanks!!
I live in the United States, and the first thing I would cook is turkey chili!
I’m in Colorado and i would make Chili, fall is coming soon, that means snow.
Hi Nagi, I live in Brisbane, Australia.I love your site. Last weekend I made your KFC Oven Baked Chicken Tenders – WOW, Yummmyy!! Had some uncooked pieces in the fridge over nite and shallow fried them for a snack the next day. Equally yum! First thing I would cook in the Dutch Oven (my choice) is your Port Braised Lamb Shanks as I don’t have anything to make them in yet.
Thank you for sharing your world with us. It is sooo tasty and inspiring. And thank you for this fabulous giveaway and to the nice people at Chasseur.
I live in the U.S. I now want to try to make this soup, however chicken and dumplings is what I probably would make first.
I live in Florida in the USA and would love to try your French Onion Soup in the French cast iron pot. I have always loved French Onion soup but have never made it.
After I’m chosen as the winner of the chasseur cast iron casserole pot, I would head straight to my favourite room in the house- my kitchen- and cook a scrumptious coq au vin. Yummy. I live on the northern beaches in Sydney( the best spot in the world).
Yes it IS the best place in the whole world!!! 🙂 Isn’t it a glorious northern beaches morning??? N xx
Hi Nagi I Live in Adelaide South Australia and I reckon I would cook either your red wine lamb shanks or the slow cooked chilli con carne. I have made both of these dishes before in a “cheap cousin” cooker compared to the Chassuer cast iron casserole pot, however both recipes were scrumptious with the meat being tender and pull apart. So i would love to try either one of these meals again but in fancy blue Chassuer cooker!
Cheers Holly
Fairview, Texas
I would cook Bacalao (Fish Stew) that is on my blog. It is one of my favorites.
I am still looking for a great French Onion Soup; so I will be trying yours.
Annapolis, Maryland USA. We love posole, and it is getting to be cool weather here. Thank you!