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
Hungry for more? Subscribe to my newsletter and follow along on Facebook, Pinterest and Instagram for all of the latest updates.
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 there! I live in Japan. The first thing to cook with this marmarvellous casserole pot is a home made Japanese curry for sure! Lots of veggies and beef..yum! This pot will make curry extra tasty:)
I live in New Hampshire in the USA. I am a huge fan of ethnic foods so I would definitely make a curry as my first dish! Hope I win!
Slow braised short ribs for sure! A winter time favorite in my newly-wed household! And with winter slowly creeping up on the US I would definitely be super happy to win these ?
Hi! I’m from the US..and would love to win this prize..I love to cook and experiment with new recipes..I would love to use this prize to slow cook a roast to make shredded beef for tacos and def want to try the French onion soup recipe..Thank you so much!
Im from the USA–the first meal I would love to mske in this dutch oven is veal osso buco!
Yummmm….I’m in America! I would love to braise short ribs with Barolo in a Dutch (French) Oven. I typically make this in a stove top safe slow cooker insert.
USA! And I’d probably make a big pot of chicken noodle soup or a pot roast with carrots and potatoes!
I LOVE French onion soup and I’ll definitely be trying this recipe!! I live in the US. Thank you!!
I live in Australia. The very first thing I would cook is my Mum’s delicious chicken casserole! It’s creamy, full of vegetables and flavour!
Hi there! I’m from the USA and would definitely try the French onion soup recipe on this page. I’ve never tried making it before so I’d love to have my start using the best! 😀
Hi! I’m from the United States. My husband and I LOVE cooking together, sooooo the possibilities are endless. Curry, shashouka, chicken/gnocchi soup…
From San Francisco, California. I think I’m going to do pumpkin soup with sage, topped with pan seared foie gras with balsamic reduction. Pumpkin season now remember.
Hello…I’m from the USA. The French Onion soup sounds great!
Thank you very much.
Hi,
I’m from Sydney Australia and currently developing a new found love for cooking. I would give the French Onion soup a try sounds delicious!
Hi, I’m from the United States and I would love to try and make the Coq au Vin. 🙂 Thank you for the opportunity to try and win on of these beautiful French ovens.?
I live in the U.S. and love cooking, especially savory dishes! If I won, I’d start with a hearty stew!
I’m on the beautiful Gold Coast in Australia and I’d be stoked to win one of these!! I’ve never owned anything that goes from stovetop to the oven – so the list is long – but i think first of all I’d cook an old fashioned slow cooked roast lamb … with all the trimmings. Of course! Xxx
Hafa Adai, from Saipan, Nagi! Are US territories also part of your sweepstakes geography? Such beautiful cookware! ?
I’m from Ontario, Canada. The first thing I’d make is some Hungarian Goulash.
Hi Nagi! I’ve been following your instagram account for some time and your recipes are the best. I’m currently living in San Francisco, USA, and if I win one of the casseroles I would love to try your french onion soup! It’s been ages since I’ve had it, my family used to do it from time to time (we are from Barcelona, Spain, and our cuisine has a bit of a french influence) and I miss it a lot!
Thank you for doing this giveaway 🙂