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 Nagi!
I live in Sydney, Australia.
The first thing I would cook would be a delicious creamy chicken risotto!
Love your blog 🙂
hi nagi . I would let my wife choose her favourite recipe and cook it for her on the occasion of our 40th wedding anniversary on nov. 20 this year .regards and thanks for the recipes.
I’m from Perth, Australia I would love to make beef cheeks in red wine in my new “French Oven”.
I live in Oakland, California. In addition to continuing to work my way through all the recipes on your blog (of course), I would love to make my family’s drunken pork in that dutch(french) oven! (To be honest, we call it my family’s recipe, but I think it really comes from Marcella Hazan 😉 )
I live in Sydney, Australia
I would cook lamb shanks in a ragout that my Mum taught me. It is so tender, succulent and yummy. I have cooked it in my glass Pyrex casserole dish and its just not the same flavor as she get from her cast iron dish. This would make my year and I could treat my whole family to one of our favorites giving Mum the day off! Thanks for your fab recipes and great competitions
I am from Saskatoon, SK in Canada. I have 3 different sizes of cast iron frying pans which I LOVE to use and would love a Dutch oven.
The first thing I would make is Avgolemono Soup (Egg and Lemon Soup) or maybe Oso Booko (excuse the spelling)
I have been watching and cooking your recipes, Nagi, for about a year now. You always have great things to cook and eat…my favorite things in the world to do!!!
The first thing I want to fix in one of the beautiful cookware pieces is the French Onion Soup, and next, is my mother’s Homemade Beef Chili. Everyone who eats my 92 1/2 mother’s chili insists on having her recipe. There’s nothing better than Homemade Love, don’t you think?
Thanks, Nagi; you’re the best!!!
Patsy
PostScript
I’m also a Texas girl………and dang proud of it!!!
Bonjour Nagi,
I was born & raised in the south of France (2 hours north of Barcelona, Spain) and now live in Colorado, USA. I do not own any cast iron cookware yet 🙂 and I would love to make CASSOULET as my first dish. MERCI for choosing FRANCE as your cooking inspiration this week. I love your recipes!
Hi – I am from Australia. Why just cook one dish if I win two pots? I think I would try both the French onion Soup and the Coq au Vin 🙂 Helen
Bonjour Nagi,
Born & raised in the south of France (only 2 hours north of Barcelona, Spain- I know, right?!) I now live in Colorado, USA. I do not own any cast iron cookware and would love to make CASSOULET as my first dish. MERCI for choosing FRANCE as your cooking inspiration this week 🙂
I live in Texas in the US and would love to make my husband’s famous red wine beef stew in this cookware!
Wow…how generous of Chasseur and you, Nagi. I live in Brisbane and would love to bake my sourdough in that beautiful blue ‘French’ oven.
I live in Sacramento, California. I would love to make your French Onion Soup in the French oven!
Hi Nagi,
Greetings from Athens – Greece.
The first think I would probably cook would be you coq au vin, and the second one would be a no knead bread.
Congrats for all your recipes.
Hello from Ohio
The first thing I would cook in this lovely pot would be some sort of chicken stew. It would be so delicious cooked in this pot. I love the color blue it is also.
Hi all!
I live in Oregon (USA) and would love to cook a beef stew or anything chicken in one of those beautiful pots!
I live in bc Canada and would make a big winter stew
I’m live in Atlanta, Georgia. I would love to cook this french onion soup in my new beautiful pots!
I live in the most beautiful country in the world- Finland! 🙂 I would love to cook lasagne for my husband. He is my everything and brings so much love and laughter to my life 🙂 I would also love to cook lambpot for my family!
I live in Canada and seeing as fall is approaching I would probably make Boeuf Bourguignon