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!
Hello! I live in Tasmania, Australia.
If I won if make a slow cooked goat curry!
Hi, I would make gammon with cabbage in the beautiful blue pot for my Irish husband (who also speaks French). We live in Sydmey, Audtralia.
Omg Nagi.. your so nice, your sharing all your delicious recipes and now these beautiful Casserole thanks, I’m from Mexico but I’m living in USA and the first thing I’ll would cook is Carne en su Jugo.
Lamb shanks…with rich red wine sauce.
Hi, I am from Victoria. I will love to cook nonya chicken curry if I win the French oven.
Laura from Australia.
My Chinese-Malaysian grandmother has just taught me to make Rendang Terlagi-Lagi (come-again Rendang) with her cast iron set. I will definitely cook this first to see if I can perfect her recipe!
I’m from the USA and I think that the first thing that I would probably cook is a gumbo. Thank you.
I’m not sure what looks better: the pot or what’s inside! I’d make boeuf bourguignon: it’s the perfect way to spend a lazy saturday around the house, puttering around while delicious smells fill the kitchen.
Hi Nagi! I’m Jennifer from Montréal, QC Canada. Thank you so much for doing this give away!! My first pick would have to be the Chasseur cast iron casserole pot. I’d have a big family dinner and would make my late mum’s African, spicy ground nut soup/stew with chicken and garden eggs. It was our family favorite!!
Also love the French line up of recipes! I’ll try them all!
What an amazing competition. I live part of my time in Australia and part of my time in Egypt. I gave all my enamelled cast iron cookware away when I packed up to move to Egypt and have regretted it ever since. What would I cook with a new “French” oven? There are so many possibilities, where do I start? Firstly, I’d make a loaf of no-knead bread and bake it in the La Chasseur to make it beautifully browned and crispy. Then I’d make Coq au van. Something that I can’t eat when I’m in Egypt because of the wine and bacon. And now I’m feeling incredibly hungry.
Oh this is so exciting… England is included in this fantastic give away… I love the shallow pot… OBTW, I’m Gayle and I would cook stir fries, casseroles and sauces for two… I would use loads of Nagi’s wonderful recipes… Thank you for the offer and the wonderful French Onion Soup recipe… I love it..
Hello from Sydney (Australia of course).
This fellow Sydney-sider would cook a good old-fashioned pot roast (which I have never tried before, come to think of it…)
USA, braised beef ragu
Hey. Looks amazing and I don’t even like French onion soup
Wow, thank you SO much Nagi for making this open (almost) worldwide!! I’m always so sorry to see all the great giveaways only open to US residents. I live in Europe. And yes, that duck egg blue pan is stunning! I’ve been yearning for a Dutch oven for the past year and the first thing I’d make in it would be some creamy, spicy curry! Thanks again for the generous giveaway!! 🙂
I’m still the cooking newb out here in Los Angeles, but I love the recipes you post; definitely motivating (and mouthwatering). These pots are gorgeous, but also sound like they’re made with amazing quality. I would love to explore the delicious potential they offer, starting with making my mom’s slow simmered red wine, rosemary and beef roast stew. I’ve never been able to replicate the taste–cooking, like other things in life, tends to get away from me. But these pots make me hopeful!
Hi this is Tobi from Germany.
The first thing I will cook would be a great goulash. An awesome dish I haven’t eaten for a while…
Hi from New Jersey, USA (originally from Sydney Australia). I just love these pots! Hoping I’m lucky enough to win one and make our pasta sauce with short ribs (family recipe). We just canned over 500lbs of jersey plum tomatoes so we will be stocked with sauce for our sunday dinners for the year. Would love to make the french onion soup recipe. It looks divine!
England ..and first thing to cook would be lamb goulash. Thank u x
Hi Nagi,
First of all, I love your site and have tried some of your recipes…..all DELISH!! I am from Wisconsin in the USA. Since it’s Fall season now, I would like to make some kind of soup. I think your french onion soup is calling my name!