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!
Jim from Illinois US ,I repost your recipes to Pinterest, they get repinned quite frequently. I,m the main cook for my father and he’s loved all of your recipes. Thanks Jim PS I’ll be fixing this next week The 5 Star are for your great site.
Hi Nagi!!
I would love to cook slow braised lamb shanks, the kind you cook for so long they fall of the bone. So delicious and it just makes your belly happy! I live in Australia
Hi Nagi, my name is Bill and I live in America (North Carolina) I am going to make the French Onion Soup this weekend. I look forward to sharing the experience with my two adopted daughters (ages 8 & 10). I would love to make beef stew in a new French oven 🙂
Hello there Nagi, greets from Ventura, California!
I’d love to make a three cheese Mac’ n’ Cheese with my mother.
Thanks for the great recipes and cheers.
Hi Nagi, I’m an Aussie, first dish. Slow cooked lamb shanks with guiness.. I’m drooling just thinking about them. blue is my fav colour
Hi Nagi,
I am so thankful i stumbled onto your site! I would love to make your creamy chicken in White wine sauce! I have loved every recipe I have tried so far..I live in America. Thanks for being awesome!
Hi Nagi, thank you so much for your beautiful recipes! I am completely addicted.
I am a Frenchman from Paris living in Coogee NSW. If I win one of the Chasseur pots, I will remain traditional and cook Beef Bourguignon with Robuchon’s potato purée.
Thank you!!!
Hi nagi,I love all of your recipes.I’ve made a lot of them..I would make your coc August vin first.I live in auburn,pa.
I love to cook and try new recipes.l would be thrilled to win either pot.keep those recipes coming!
Hi Nagi, I love your recipes! I live in the USA in Mesquite, Nevada and the first recipe I would make is your Guinness stew…have been wanting to make this but don’t have the right size pot as mine got too old…had to throw it away.
Hi Nagi, the very first recipe I make will be goat curry, followed very closely by coq au vin and French onion soup (sound really good) for a big night out pick me up! Thanks Nagi, I look at your website every week, I’m in Melbourne Australia.
Annie from the US; French onion soup, which I adore and love to make. 🙂 Thanks!
Hi my name is Alan from Melbourne, Victoria and no doubt it would be the Coq au Vin after looking at the rich sauce in the photo. If its as good as some of the wings in the ecookbook (Baked wings) it will be delicious.
Hi Nagi – My name is Tracy & I live in Australia. Cant wait to make a slow cooked Massamam curry – full of flavour yum!!!
From Canada – I would love one of these pots. First thing would be Lamb Shanks, but will also do French Onion Soup, Chicken Masala, Coq au Vin and so many others. I would use this pot regularly as I love to cook and cast iron does it the best. I enjoy all your recipes and usually try a new one at least once a week. Thanks for the recipes and opportunities.
Hi Nagi! I’m in the US! I thought a curry would be my first choice, but that Guinness stew recipe ?
My first dish i would create in my new casserole pot wouid be my favourite mushroom Risotto
X
Hi Nagi. I live in Brisbane, Australia. I love your recipes and would love to try the Coq au Vin if I won the Chasseur set.
Thankyou for all your inspirational ideas.
I am in Australia and I would LOVE the French oven. I would want to cook my Mums pumpkin and Sweet Potato soup in it, enough so that I can freeze some for emergency meals when work is too much and I could not be bothered.
Hi Nagi! Love your recipes! I live in Breckenridge, Colorado, USA. I would definitely make your Coq au Vin, Julia’s Boeuf Bourguignon, Indian Butter Chicken, … so many dishes! I love to cook. Problem would be which one to cook first!
Hi Nagi I live in beautiful Queensland Australia. The first meal I would cook would be Beef Cheeks slow cooked in red wine. My family would of course be at the table when this delight is served. Yummo