Perfectly caramelized onions, a rich beef broth and melty cheesy toast, makes this classic French onion soup a go-to when you need a little comfort food! It’s a hearty soup recipe too good to miss!
This easy French onion soup recipe was originally posted in September 2015, but has been updated with new recipe details, pictures and small recipe tweaks.
I love French onion soup.
How could you not?
There’s onions that have been cooked down so they are sweet & delicious, crusty bread on top (soaking all that beefy broth) & copious amounts of gooey melty cheese.
This winter soup is definitely a meal in itself. With a nice glass of red wine, you’re set!
You will use quite a bit of onions in the recipe, but they quickly cook down and, besides that, this is French onion soup, isn’t it?
They say don’t cry over spilt milk, but you may cry over onions when you have to slice them; I know I do 😉
And, fair warning, your breath may not thank me after eating this soup, but your belly surely will! It’s worth it, though!
What is French Onion Soup?
Essentially, French onion soup is a big bowl of comfort food, which includes caramelized onions and beef broth with a piece of melty, cheesy bread on top.
For this onion soup, you’re gonna need:
- Onions (of course, like red, white, or yellow (or a combo of those))
- Olive oil & butter
- Flour (to thicken things a litte)
- Seasoning, like salt, pepper and thyme
- Beef broth
- Worcestershire sauce
- Balsamic vinegar
It’s amazing how some humble ingredients, like onions, along with a few other things can and be transformed into something so special!
How to Make This Soup
Full details in recipe card below, but here are the basics:
- Caramelize onions (easy step by step instructions to caramelize onions here).
- Add minced garlic and cook.
- Deglaze with a little wine, scraping up to get those little brown bits (hello flavour bombs!)
- Stir in flour (this will help thicken things).
- Add salt, pepper and thyme.
- Pour in beef broth.
- Pour in Worcestershire sauce.
- Next, pour in balsamic vinegar.
- Stir and cook a little while.
- Lay French onion soup bowls on a sheet pan and portion soup into them.
- Top soup with bread.
- Pile on shredded cheese.
- Broil until the cheese melts.
- Carefully remove from the oven.
- Garnish with thyme (if you like).
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Do I Have to Use Special French Onion Soup Bowls?
Nope! Not at all.
You do, though, have to use oven safe bowls when broiling the cheesy toast!
Tip: Don’t have oven safe bowls? Skip putting bowls in the oven. Broil the cheesy toast separately and place on the hot soup after.
What Can I Use Instead of Gruyère Cheese?
I love Gruyère here because it’s tasty, rich and melts well.
However, if you don’t have Gruyère cheese on hand (or simply rather use another variety) try plain Swiss cheese or Fontina.
Tip: Shred your own cheese for optimal freshness and flavour rather than purchasing pre-shredded.
What Can I Use Instead of White Wine? Can I Omit the Alcohol?
Instead of white wine, try red wine, sherry or even brandy.
Not into the alcohol? Deglaze with beef broth.
How To Thicken Soup
You can thicken French onion soup in various ways:
As I did in this recipe. Sprinkle over top when onions are cooked.
You’ll want equal parts cornstarch and water. Start with 1 tablespoon each of cornstarch and cold water. Mix together before stirring into soup and heating a little until thickened. You can stir this in during the last couple of minutes of cook time.
Reducing the soup on a low simmer
Simmer until you’ve reached your desired consistency.
Adding more caramelized onions.
More onions means a denser consistency!
Use soup to thicken
Remove about a cup of soup from the pot and blend with an immersion blender. Then, stir back into the pot.
Can I Make a Lower Carb Version?
Yes! Even though it’s not as traditional, omit the bread. Simply top soup with cheese and broil until melted.
More Helpful Tips
This soup is super simple, but does take time (especially because there are caramelized onions involved). Just have some patience and it will be well worth it!
Like with any soup, use a good-quality broth. Homemade beef broth would be awesome (like this beef bone broth from Epicurious), but if you don’t have that store-bought is perfectly fine.
Speaking of broth, I like to use an ‘unsalted’ variety. If you use ‘regular’ or ‘low sodium’ consider adjusting the salt added.
If you want to broil the cheesy toast in the oven on top of the soup, don’t fill your bowls to the brim. Once you add the bread, it will displace some of the liquid.
Use a hearty bread that can hold up to the broth. I like focaccia or ciabatta (or something similar). Of course, no matter what you put on there it will absorb some liquid (which is awesome), but you don’t want to use a basic white bread here.
Use a sheet pan to make things easier for putting those bowls in the oven and taking them out. Plus, the sheet pan will catch any spills, meaning less cleanup.
More Caramelized Onion Recipes
Hope you love this classic French onion soup recipe as much as we do!
If you make this French onion soup recipe, please leave a comment below. Love to know how you enjoyed it!
French Onion Soup (total comfort food!)
- 2 tablespoons butter
- 2 tablespoons olive oil
- 3 pounds yellow onions , peeled and sliced about ⅛ to ¼ inch thick
- 2 cloves garlic , minced
- ⅓ cup white wine
- 2 tablespoons all purpose flour
- 1 teaspoon dried thyme (or 1 tablespoon fresh thyme)
- ¾ teaspoon salt (or to taste)
- ½ teaspoon black pepper
- 6.5 cups unsalted beef broth
- 1 tablespoon Worcestershire sauce
- 1 teaspoon balsamic vinegar
- 6 slices bread (your favourite bread)
- 1 tablespoon avocado oil (optional)
- 1.5 to 2 cups shredded Gruyere cheese (about 6 to 8 ounces)
- Fresh thyme leaves (garnish, optional)
- In a large pot or high-sided pot (I use a large enameled Dutch oven) on medium low heat add butter and olive oil. When butter is melted add ⅓ of onions. Stir to coat in butter and oil and cook 5 minutes, stirring periodically.
- After 5 minutes, add another ⅓ of onions, stir and cook 5 minutes. Continue with remaining ⅓ of onions. Note: Because we are caramelizing a lot of onions here, I like to add in batches rather than all at once.
- Cook for about 45 minutes in total, checking on every 5 minutes or so, ensuring they aren't burning and scraping brown bits on bottom of pan and incorporating into onions. Every once in a while, add a splash of hot water to loosen any excessive brown bits and encourage the onions to cook, no more than ¼ cup at a time (up to a cup in total).
- After about 45 minutes, add garlic and cook 1 to 2 minutes.
- Once you've reached your desired caramelization, deglaze onions with wine. Stir, scrapping up any more brown bits. Cook 1 to 2 minutes. Stir in thyme, salt and pepper.
- Stir in flour and cook 2 to 3 minutes.
- Pour in broth, Worcestershire sauce, and balsamic vinegar. Stir. Bring to a light simmer and cook 15 to 20 minutes. Taste for seasoning. Portion into bowls.
- Brush each slice of bread with a little avocado oil (optional) and place on top of soup. Distribute cheese among bread slices. Place bowls on a baking tray.
- Set oven to broil and cook until cheese is melted and a little golden. Carefully remove and garnish with fresh thyme, if desired. Enjoy! Serves 4 to 6.Note: If you don't have oven safe bowls, omit putting the bowls in the oven. Rather portion out the soup and toast the bread with cheese separately, putting on top of the soup when serving.
- This soup is super simple, but does take time (especially because there are caramelized onions involved). Just have some patience and it will be well worth it!
- Like with any soup, use a good quality-broth. Homemade beef broth would be awesome, but if you don’t have that use a quality store-bought variety.
- Speaking of broth, I like to use an ‘unsalted’ variety. If you use ‘regular’ or ‘low sodium’ consider adjusting the salt added.
- If you want to broil the cheesy toast in the oven on top of the soup, don’t fill those bowls to the brim. Once you add the bread, it will displace some of the liquid.
- Use a hearty bread that can hold up to the broth. I like focaccia or ciabatta (or something similar). Of course, no matter what you put on there it will absorb some liquid (which is awesome), but you don’t want to use a basic white bread here.
- Use a sheet pan to make things easier for putting those bowls in the oven and taking them out. Plus, the sheet pan will catch any spills.
- Nutrition (estimate only) based on using 1.5 cups of cheese and 6 servings.
Nutrition information (if provided) is provided as a courtesy and should be considered an estimate only. Ingredients can vary and Girl Heart Food makes no guarantees to the accuracy of this information. It should not be considered a substitute for a professional nutritionist’s advice.