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/America. Your photos are fabulous! I would love to try your Coq au Vin recipe.
Hi Nagi, my name is Amy and I live in the UK. I have been on plenty of recipe websites, but I must say yours is my favourite. So many things that I want to eat and are simple to make. If I were to win one of the chasseur pots I would honour the win by making this French onion soup recipe! Although, my favourite dish I have made so far is the creamy salmon orzo. Delicious!
Being in South Dakota, USA, I would make a braised short rib stew. It would be perfect for the fall weather and soon to be freezing temperatures!
I want to make a delicious stew, or Lamb dish…. Oh this is exciting.
I’m from New York City, and the first thing I would make would absolutely be Coq au Vin! Your most recent post has me craving it 🙂
Love braised lamb shanks, and guess what? They are from Australia. Cooking in a small skillet, which is pretty tough. Would just love a bigger one to feed my family of four.
USA and would make braised lamb shanks.
I would make my favourite, the classic hearty French dish Boeuf bourguignon. I can’t wait for the aromatic flavours and aromas to engulf my kitchen, and enjoy the left over French wine as i wait for it to be ready. Plus I hear it was one of Julia Child’s favourite. I’m of Italian heritage based in Austrslua.
Live in USA/America. I would love to have this pot to make my chicken/turkey tettrazini in.
BTW, French Onion Soup gets wine in it. Some use a red & some like it with white wine.
I’m from California, USA. I would be making the Guinness stew since we always have it in our fridge and the cold weather will start soon here.
I am from Canada, and the first thing I would make with my Chasseur would be a beautiful Cioppino, then a hearty, warming Irish Lamb Stew!
I would love a French pot. In the winter I cook on a wood burning stove and this type of pot is perfect for slow cooking/braising.
I would love the French cookware, in the winter I cook on a wood burning stove and this type of cookware is perfect for slow cooking/braising.
Im from the UK and would have to do lamb shanks.
Thank-you for your hard work. 🙂
I am from AMERICA and the first thing I would make would be COQ AU VIN.
Hi Nagi! I love your blog, your recipes and photography are amazing. I live in Canada and if I were to win a Chasseur pot, I would love to give French Onion Soup a try! Thanks Nagi! 🙂
Hi Nagi! I love your website! I love your recipes! They are as easy as they are delicious! (the garlic cheese crack bread is my favorite) (parmesan shortbread biscuits a close second!) I live in the USA, and if I won a Chasseur pot I would make a Guinness stew, or braised short ribs-my husband loves lamb, so maybe lamb shanks-the possibilities would be endless!!!
Hi. I love your posts and would love to see them continue. as I don’t eat red meat, I would make Cioppino first.
Hello, from Coquitlam, BC, Canada! I love all your recipes! I would love to try your French onion soup, it looks so luscious! I would love to own the French casserole pot! Actually, either one, both are beautiful and useful. I don’t have any cast iron pots. Love, love, love your site! Thanks for all the time you put into it ❤️
Hi Nagi, thank you for all your wonderful recipes and beautiful photos. I live in Mississauga Canada and up until last night I would have said lamb shanks would be my favourite to cook in the casserole. However, I had the most delicious veins osso bucco at my in-laws last night and now I can’t wait to make it myself.
Keep those delicious recipes coming!