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!
You have sent this to Barry Humphries, haven’t you? At this stage of his life he would get a real; smile from the numerous Dame Edna Everage comments 🙂 ! Having met him. methinks he would love the classic soup as much as I do, tho’ am not aware whether , like me, he actually does take the time to caramelize the onions . . . atta Dozer . . .
😂
Yum, been years since I’ve made French onion soup. Brilliant idea to do the cheesy crouton separately!!
Also wanted to mention that I love the way you’ve been reformatting your pages lately (the portion above the recipe). The actual recipe portion of your pages have always been exceptionally well written and easy to follow (love, love, love the notes – I always like to know all the details and reasons why, etc., but I know a lot of people have different priorities, and having that in the notes keeps the instructions well organized and, well, “sleek.”).
While I’ve always enjoyed reading about your thoughts on all things food-related, I particularly like the way you’ve broken the text above the recipe into sections with subheadings/titles, added numbered step-out photos, judiciously bolded the occasional important word or phrase, and included bullet lists. Before I retired I worked in city government and often produced public information materials or web pages for my department. I learned the hard way that different people take in information in different ways, and it was a challenge to present important information in a way that’s fast and easy for people to absorb. I think you’ve cracked the code with this newer format, Nagi.
Your food has always been awesome, you work hard to perfect techniques to ensure big flavor from minimal effort, and your recipes are easy to follow. This latest tweak makes yours one of the most professional blogs out there. (And by tweak, I don’t mean to imply it’s a trivial thing – I know the work that goes into it, whether from scratch for a new post or redoing an older one.) Even though I haven’t seen any comments about it, I’ll bet your readers have noticed the difference in how streamlined your site has become (of course, we all appreciate the limited advertising and daily dose of Doser!).
Didn’t mean to write an essay. Just thought you should know.
Cheers!
Barbara
Thanks so much Barbara, it means a lot to get such great feedback!! ❤️
Hiya Nahi
Just curious – is it possible to finish the soup in the slow cooker? After the flour put the contents back then add the broth?
Obviously it will take longer but would it be detrimental to the taste?
Thanks and scritches to darling Dozer
I’m sure you could, just follow the recipe until step 4 then return it to the slow cooker for 2 hours on low
I actually did the full recipe in my slow cooker.
After the onions had cooked I skipped the caramelisation part and added the flour. I left it to cook for about 45 minutes*
I added the liquids and dried thyme, gave it a good stir and let it cook on low for 3 hours.
Then I had a bowl and left my slow cooker on keep warm until I remembered it was still on hours later lol
It still tasted wonderful the next day and I have two bowls worth in my freezer too.
*I only meant to leave it 15 minutes but Boo dog wanted to play tuggy so we played tuggy
Love French Onion Soup, you make it look so easy.
Dozer wearing the onion glasses reminded me of my Mother in law cutting up onions when making pickles in the fall . I walked into the room and saw her wearing swimming goggles, happy as could be and the onions didn’t bother her a bit. She was a typical stay home Mom that could cook a fabulous meal on a wood stove and you wouldn’t even realize she was cooking.
Thanks for conjuring up that memory for me.
Dozer wears those glasses well. Lol
The best to you both
Cat.
What a great memory Cat! ❤️
Actually, Dame Edna Never looked as good as Dozer in his fancy eyewear, and he was such a cute puppy too. I imagine it was love at first sight, since who wouldn’t be smitten with that little bundle of fluffy joy?
I’m not personally a fan of onion soup, but have made it for those who like it, and might do so more often after reading this post. Great simplifying tips! Especially, the genius cheese toast tip–so much easier to make and like that it’s safer to both handle and eat, too.
😂😂
Nagi, you are the best. First thing I do on your blog is to look for Dozer.
Truly one can love a dog as much as anything. A ray of sunshine is your work.
Thanks Cameron, what a great compliment!
Just loving the pic of Dozer channelling Dame Edna 😉
Another epic recipe too x
Carol in Auckland
😂
Genius video.
Briefest way to impart knowledge.
Keep up the good work.
Blessings
Hunter
Thanks Hunter!
Dozer is NOT amused (but very glamorous!)
😂
Where I live, in Western Canada, we have LOTS of onions! This soup, though so rustic, is elegant and the best is made down east in Quebec. Such a humble list of ingredients but this is a case where the whole transcends the parts!
I’ve avoided making French onion soup because of the time commitment in the kitchen and the fact that we don’t have a convenient to use broiler to finish the cheesy croutons. Your slow cooker method and doing the cheesy croutons separately solves that. Question: my brother gave me a Ninja Pot multi cooker that can cook like a stove top or a slow cooker. Would it work to sweat off the liquid on the stove top function before browning on a slow cooker function?
Sounds like a great idea David!
Simplist dish ever Nagi! Will definitely try it some time.
😂😂 am weak here …super goggles that somebody (Dozer) does not even care they’re on his face …
Enjoy the day! Hugs …😊
PS: I am thinking of trying that Chicken Stroganoff on Saturday. Will let you know how it turned out.
You must try it! I hope you love the Strogg!
Oh Dozer, my lovely, you remind me of Dame Edna Everage with those shades. Big hugs!!
French onion soup is one of my favs. Must try your version. It looks mouthwatering especially with that cheesy toast on top. YUM!!!
Cheesy toast is a must! 😂
Caramelized onions in a 14 hour pork/chicken ramen stock plus tare…French Onion Soup doesn’t get any better than that. Has to be gruyere cheese.
Yum!!!
So easy.. I added a splash of white wine, and about 1\4 teaspoon thyme. No added salt or pepper. I toasted sourdough bread and placed on top of soup. Added gruyere cheese. Melted with broth because i was so ready to indulge. Yum Yum.. Will definitely make this again. Next bowl I’ll melt the cheese.
Glad you enjoyed it Leah!!! Thanks for sharing your feedback 🙂 N x
Hi Nagi,
I can’t wait to make this! I was wondering if using normal beef stock/broth (as opposed to salt reduced as you specify) would ruin the soup? I can imagine it would turn out too salty but just wanted to know if you think it’s doable.
Cheers! 🙂
Hi Alison! It will be fine 🙂 I like to use salt reduced to cater to differing salt requirements, but it’s not too salty 🙂
Thanks so much for your response, Nagi. That’s a relief, since I bought 1.5 litres of normal stock in anticipation of making this and then read the ingredients more carefully, haha. x
Can’t wait to try this!!!
Hope you love it Jeanette!
Dear Nagi;
I love many of your recipes, but stirring onions for 30 minutes? Yikes!
I’ve heard that it’s possible to make caramelized onions in a slow cooker with very little effort. Could that technique somehow be incorporated into your onion soup recipe?
Hi Gerry! I’m afraid I haven’t tried that yet, but I will update it if I do! I’m sure you can google it 🙂 N x
Hello Nagi
I am from Holland and fond of your recipe’s!
Looking for “coq-au-vin I ran into your recipe for onionsoup
I am fond of it,since my first, almost 50 years ago at “Les vielles halles deParis” in the middle of the night.
From that day I am in love with it and make it myself many times.
However I do little things different, f.e.:
Instead of 1,5 litres of beef broth I use a little less and when the soup is almost ready I add a glass of dry white wine.
I also use 1-2 cloves of garlic which I add when the onions begin browning.
However I never use flour but just a little bit of cornflour that thickens the soup a bit, but keeps it clear
Something for you to try?
So now i go to cook your coq-au-vin.
Greetings, Adriana
I LOVE HEARING THAT Adriana!!! N x
Right, so this might sound disturbing, but hanging out here is fast turning into an everyday ritual 😀 I’ve just had dinner and back here for more visual eating. I’m already waiting for Wednesday to create your bangers n mash recipe.
Nagi, I noticed, your onion soup looks a lot like soup and not just stock with onion floating in it. How do you get it to be so brown?
Ha! I LOVE hearing that!!! The colour of the soup is from both browning the onion and the stock. The browning on the onion seeps into the soup while it simmers, plus from the base of the pan. 🙂 N xx