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!
Fantastic. I am in Alabama in the US. I would love to make Craw fish Etouffe when the weather turns cooler and Ratatouille next summer when the fresh vegetables come in at the market.
Nagi, can’t wait to try this soup. I live in Ohio, USA, and would go for the shallow casserole pot as I have a fantastic Dutch (French) oven already. Love your recipes and reading everything!
I am an old geezer widower in Beaverton, Oregon, U.S.A. I was just starting to cook inedible stuff when I stumbled onto your website and found that I could really put together some pretty decent and yummy stuff. One thing I have never felt competent to try is good macaroni and cheese made with honest Tillamook Extra Sharp Cheddar. That is the first thing that will go in the Chasseur pot.
Hi. I live in the U.S. and would love one of these beautiful pots. So many ideas are running through my mind right now to make French onion soup, beef stew, chili. I could go on and on.
Dear Nagi,
I simply love your recipes (and your mom’s, too!) thank you for all these great inspirations!
I would also love to try and make your Ham potato and corn chowder in a Chasseur (or maybe it would be a White Enchilada Soup with Chicken first… hm, still a little time to decide ;)). I am from the United Stated (Florida to be exact) 🙂
Definitely the French Onion Soup, yum. San Diego, CA, USA
Bon Appétit
Buon Appetito
I am in England and tbh this recipe sounds too perfect not to do, although my photos won’t be as good as yours by a very long way!! At the moment here I am harvesting all of my pumpkin and onion for storage/soups and chutneys – yum. Plus I have *such* crush on Manu (don’t tell my husband!) Xx
Over 20 years ago I was taking French in college. The professor was a French woman who took us off campus to her house to take the final exam. After the exam, we were invited to have a dinner she prepared for us. We scattered to different rooms to take our test. It was difficult to concentrate because all the while, we could smell wonderful aromas coming from her kitchen. When the exam was over, we all filed into her dining room and had a wonderful French meal. The main dish was a chicken in white wine sauce. I’ll never forget it and I’ve never seen a recipe that approximated it. If I win, I’m going to try to replicate that recipe. I don’t remember what I got on the exam but the dinner was an A+.
Oh, and I’m from the USA!
I’m excited for the French-themed recipes! I literally just got back from a trip to France two days ago where I ate tons of yummy food and so if I were to win this giveaway the first thing I would make in the French ( 😉 ) oven would be a Boeuf Bourguignon, since that was my last restaurant meal in France. I live in Germany, by the way! 🙂
I love French onion soup and I sometimes use vegetable stock in mine. First dish might be a lovely mole chicken or a chili. A stew or pot roast is good for the winter, shepherds pie, casseroles, and soups, oh my! I would love either pan and am sure that it would become my favorite. cooking pan! I am in USA. Thank you
I live in Gatineau, Quebec, Canada. If I won. If I won My Chasseur cast iron casserole pot, I would cook either the coq au vin, which I have cooked using your recipe and it turned out fabulous and very tasty as well. Or the Lamb Shank which I haven’t tried yet but my wife really enjoys lamb so I may try your recipe soon.
I would make cassoulet in this beautiful pan.. I’m in the U.S. and have my fingers crossef
Hi Nagi,
Thanks for making this give-away possible – they are both wonderful pots. My hubby just passed away this June from cancer. His number one meat love was lamb – so for sure , if I win one of these beautiful pots, I will be making braised lamb shanks in his honor.
Hello, I am from US in Colorado. The leaves are staring to turn and it would be great to have that pot to make a good batch of chili!!!
I have made French onion soup for many years in an old heavy aluminum dutch oven and it is unbelievably delicious. I carmelize my onions for a long time, and my French onion soup process takes at least 2 days hours from start to finish. I would love for my French onion soup to be the first thing I cook in my new French Dutch oven. I have no doubt it will be my best batch ever! I’ll have to give more thought to what I will create in the smaller pot first.
I have made French onion soup for many years in an old heavy aluminum dutch oven and it is unbelievably delicious. I carmelize my onions for a long time, and my French onion soup process takes at least 2 days hours from start to finish. I would love for my French onion soup to be the first thing I cook in my new French Dutch oven. I have no doubt it will be my best batch ever! I’ll have to give more thought to what I will create in the smaller pot first. I live in the USA.
You had me salivating at the first picture, so clearly I’d start with the soup! I’m in the USA. LOVE getting your emails!
I am from United States. I would love to make my moms recipe for Beef Stroganoff in the deep pan. The rice is cooked with 4 cans of Beef Consomme and sauteed onions and bell peppers.
I am in the USA and would love to cook a pot roast in this!!
I’m from Oklahoma, US and these types of recipes are exactly what I crave during fall! I’d probably start with my husbands favorite, curry.
Being from the South, soup and stews are comfort food and with the Fall coming, I make a lot of these but I try to make it for only 2 and it doesn’t taste right. Can a recipe be cut in half to make smaller portions?