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!
Without a doubt, my favorite French onion soup!!! Love it! I live in the USA.
Hi I live in the USA. Georgia . I would defiantly try your Coq au Vin recipe first looks delicious !
The first thing I would cook with these pots would have to be lamb shanks in red wine sauce with root vegetables. i am in Canada and have not only found you, I now have your mum too.
I think you just made my mum’s day! 😉 N x
Australia! I would definitely make your Italian Meatball Soup and Irish Stew with my brand new French Oven!!
UK and beef stew and dumplings
YES to that! 🙂 N x
Sydney, Australia.
I’d love cooking Boeuf Bourguignon by Julia Child,
The recipe sends my tastebuds wild!
Chasseur perfection for this delicious dish,
Our ultimate French cooking wish!
I have always been loyal to Julia’s Beef Bourguignon!!! I can’t wait to share it one day soon…. 🙂 N x
USA and A Creole dish called Sauce Piquante
Omg these are AMAZINGLY BEAUTIFUL!
USA and lamb shanks all the way.
I would be thrilled to win either one, but especially the french casserole! I would make Guinness stew first thing, followed by lots of soups & yummy noodle dishes!
Australia!
I would love to cook some beautiful Chicken Chasseur. It was my favourite growing up and my mum would cook it for me atleast once a week. Thank you for the opportunity to win!
I’m in Sydney Australia and I would definitely make your Guiness Irish stew and then a Bolognese sauce and then a French Onion Soup and then a … just call me greedy girl!
I would love to cook some beautiful Chicken Chasseur. It was my favourite growing up and my mum would cook it for me atleast once a week. Thank you for the opportunity to win!
USA and curry!
Good choice!!! Now I feel like Indian tonight…
Canada! And it’s a toss up between biryani and the coq au vin… Or maybe beef stew with Marsala, mushrooms, parsley and thyme, a fall favourite with us.
Nagi, I want to thank you for re-invigorating my cooking. I cook for our family which has two teens and a tween. They eat a lot, and I started to feel like I just couldn’t keep up. I fell into a cooking rut, but you have really helped me feel inspired and creative about food again. A big hug from all of us! I think everyone at my house is grateful, and my daughter loves to bake your brownies. ❤️
Sweden, I would start by cooking a Texas chili on venison that is OK for a person with IBS to eat.
Best regards
Gustaf
Australia! I would do some braised lamb shanks!!!
USA- I would make osso buco for the first time for my husband!
USA. I would make delicious lamb stew.
Hi Nagi! I’m in Brisbane and would cook everything in a French oven! I would love to improve my coq au vin and I need a dutch/French oven to do it in! I’m going to tag you in my previous coq au vin post on instagram so you can see how much help I need! 🙂 x
How awesome!! I am in America and I would love to cook many things with this, but my first would be a cherry cobbler (Witt homemade vanilla ice cream of course)!!!!! ???