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!
I live in Ottawa, Canada. I’d love to make a hearty stew with our wonderful autumn bounty; plenty of carrots, onions, parsnip, potatoes, turnips, and beef. yum!
Hi! I’m from the United States. I have been following your blog and Instagram account for forever now! I love all your dishes and have made too many to count!
Thank you for all that you do! Because of you, I eat and live a healthy lifestyle. Thank you for putting together this giveaway! It would mean the world to me.
The first dish I would cook is French onion soup! It’s always been a favorite of mine and I can’t wait for the opportunity to make it in quality cookware!
Hi Nagi,
I live in Perth Australia. I have just recently found your site and love all your recipes. If I had a Chasseur Dutch Oven I would like to try baking bread first, and then a great big hearty Beef Stew with Yorkshire Pudding!
Hi Nagi,
I live in Perth, Western Australia. I can honestly say I’ve never owned or ever used any Chassuer cookware, but I sure would love to! I think I’d have to tryout the french onion soup you have posted above, as I’ve tried to cook that once before (not that exact recipe) and it was a dismal failure to say the least.
Just loving your website and have cooked many of your recipes. Kylie x
I live in beautiful NW Montana (USA). i’d start with some yummy braised ribs!
I would make a chicken or beef braise. A one pot meal that I could serve from the pan at the table as I would love to own a shallow dish I have a large deep one but I would would love the shallow dish being retired now my budget does not allow for such an expensive item.
I live in Chicago, America and I would like to use the Chasseur cast iron pot to make french onion soup! My boyfriend’s family would always go back to France for Christmas but he decided that this year he will spend it with me! Yay! So, by having this pot I will have the time to practice all these French food by Christmas!
Hello from Greece.
can’t wait to try the French Onion Soup, or pretty much anything, don’t really care. everything I’ve tried from this blog turned out to be delicious. 🙂
We have tried a couple of your recipes and they were great. Your mothers recipe for deep fried chicken is next we had a very similar dish in Bali many years ago and this is the one we liked the best. We are very impressed with some of your recipes.
Hi Nagi
The first thing that I would cook in my new chasseur cookware is long and slow braised beef and baby onion ragout. I live in Yorkshire, England.
I live in the USA and the first thing I’d make would be the Slow Cooked Lamb Shanks in Red Wine Sauce. Nagi I would have no problem putting any of your delicious recipes in one of these Chasseur cast iron ovens. Thanks to all for the opportunity.
Living on a remote outback Queensland cattle station,
Cooking for hungry stockmen is my occupation,
Chasseur strength and durability my salvation,
Slow cooked beef stew saving my culinary reputation!
Western Queensland, Australia
I’m from the United States and would love to make some braised short ribs in that casserole dish!
I live in the Netherlands and just moved to a place for myself where all my ‘old’ pans did not work as I go from gas to induction.
As I was born and raised in France, I would definitely have a go at your French Onion Soup but I would also love to make Boeuf Bourguignon.
I live in the united States and would try a pot roast. The color wouldn’t matter since they are both beautiful.
Hello from the United States of America! I love the duck egg color. I just discovered your blog and I look forward to making ONE POT GREEK CHICKEN & LEMON RICE!
I live in Romania. I’d cook a vegan meal in it (not sure what).
Hi Nagi,
I’m Maren from Berlin in Germany (Europe).
The first thing I would cook in one of these amazing chasseurs is a French onion soup!
When I was a child, me and my dad shared a French onion soup in every restaurant that had this soup on the menu. The first thing I looked up every time was, if they offered French onion soup because I was crazy for it, and my dad too! And we still are! 😀
So the first thing I would cook is a French onion soup for my dad so we can share it this time at home!!
Wish good luck to everyone and a huge thank you to Nagi!! Thank you for this chance to win a chasseur!
Have a great week! 🙂
First thing I’d love to make in my new Chasseur Cast Iron casserole pot would definitely be French onion soup. We love enjoying soups/casseroles as they are definitely comfort foods for us in the cold white north of Timmins, Ontario! Nothing like hibernating from the cold/damp season inside made with style and class with new cookware. Thank you and Good luck everyone! Live~Love~Laugh
Hi Nagi, I’m from Australia and I would love to win a Chasseur Dutch I mean French Oven! I’ve been drooling over them for years but unfortunately they are a little out of my price range. I think I would cook Beef Bourguignon as my first dish. I love the hearty richness of beef cooked with wine. Hope I win. Cheers Denise