French Onion Soup
French onion soup is one of those recipes that feels fancy, but is actually pretty simple – if you’re willing to take your time. This version is all about slow-caramelized onions, rich beef bone broth, and that classic bread and melted Gruyere cheese topping that makes every bite worth it.
French onion soup takes time, but the payoff is well worth the effort. If you’ve ever ordered it at a restaurant and wondered if you could make something just as good at home, this is the recipe to try.
What Makes this Recipe Special
We’re making deeply caramelized onions. The real deal ones, not the 20-minute versions that claim to be caramelized.
Instead of regular beef broth, we’re using beef bone broth for richer flavor. Bonus, you don’t have to make it – you can buy high-quality bone broth at most grocery stores.
If you’ve never made French onion soup, I’m so excited for you – it’s the best kind of cozy, special-occasion comfort food.
Ingredients
- Yellow onions: They’re pretty pungent raw, but when caramelized, they have a buttery and subtly sweet flavor.
- Beef bone broth: This adds a deeper, richer flavor than standard beef stock.
- Herbs: A bay leaf and fresh thyme are simmered in the soup to add more flavor.
- Dry white wine: It’s used to deglaze the pan and also adds acidity to balance the rich broth.
- Gruyere cheese: Melts smoothly and delivers that classic nutty flavor French onion soup is known for.
- French bread: Toasted and topped with all the melted cheese.
Tips to Keep In Mind
- Be patient with the onions. Caramelizing them properly takes time – rushing this step means less flavor.
- Adjust the heat as needed. If the onions start browning too quickly, lower the heat and keep stirring.
- Deglaze thoroughly. Scrape up all the browned bits when you add the wine – they add a ton of flavor.
- Use oven-safe bowls and a sheet pan. This makes broiling the cheese easier and safer.
How to Make It
Slice the Onions
Slice the onions in half from end to end and then slice off the root end and the opposite end. Remove the peels.
Place an onion half so the ends are parallel to your knife when you’re slicing. Slice it into thin slices about 1/4 to 1/8″ thick. Do this with all of the onions.
Caramelize the Onions
If there’s one thing you shouldn’t rush in this recipe, it’s the onions. Caramelizing them slowly is what turns a simple pot of soup into something truly special. Plan on up to an hour to an hour and a half, depending on the size of your pot. I use a 10-inch pan – larger pans will caramelize the onions faster, while smaller ones will take a bit longer.
Melt the butter in the pan over medium-high heat. Once it’s melted, add all of the onions and stir them with the butter.
Cook them, stirring often, for about 10 minutes and then adjust the heat to medium to medium-low.
Cook them for 40 to 50 minutes, stirring them every so often. Keep an eye on them, during this time they will release a lot of moisture and will turn a very light golden color. If they are browning too fast, lower the heat to medium-low.
After about an hour, they will have released a lot of moisture and will start to caramelize. So, in the last 20 to 30 minutes, stir them often so they brown evenly. You can increase the heat at this point to medium, to speed up the caramelizing. You’ll know when they’re done when they are deeply golden and soft.
Deglaze the Pan
Once the onions are caramelized, pour the wine into the pan. Bring it to a simmer and scrape up all the browned bits off the bottom of the pan. Stir the flour into the onions and wine.
Simmer the Soup
Add the bone broth and stir until there are no flour lumps. Add the bay leaf and thyme. Simmer the soup for 15 to 20 minutes.
Toast the Bread
While the soup simmers, slice and toast the bread.
Broil
Heat the oven broiler to high. Fish the bay leaf and thyme sprigs out of the soup and discard them.
Place oven-safe soup bowls on a sheet pan and ladle soup into each. Top each with the toasted bread and the shredded cheese.
Place the sheet pan under the broiler until the cheese is melted. This won’t take long, so keep an eye on them.
If there’s ever a reason to slow down in the kitchen, it’s to make this French onion soup. Don’t let the long onion-cooking time scare you off – the results will wow, I promise. It’s well worth the time.
More Cozy Soup Recipes
French Onion Soup
Ingredients
- ¼ cup unsalted butter
- 2 pounds yellow onions sliced ¼” thick
- ½ teaspoon kosher salt
- ½ cup dry white wine see note
- 2 tablespoons all-purpose flour
- 48 ounces beef bone broth
- 8 sprigs fresh thyme see note
- 1 bay leaf
- 4 ounces French bread sliced (see note)
- 8 ounces Gruyere cheese shredded
- chopped parsley for garnish
Instructions
- Melt ¼ cup of butter in a 10” pot over medium-high heat. Add the sliced onions and ½ teaspoon of salt. Stir to coat the onions in the butter. Stir them often for 10 minutes and then adjust the heat to medium to medium-low.
- Cook the onions, stirring occasionally, until they have released their moisture and are golden and soft. In a 10” pot, this will take between an hour and an hour and a half. While they cook, stir them occasionally. If they are browning too quickly, lower the heat.
- In the last 20 to 30 minutes of cooking time, once they have started to turn more golden, adjust the heat to medium. Stir them often so they caramelize evenly. They are ready when they are deeply golden in color and soft.
- Once the onions are caramelized, add ½ cup of wine. Stir and cook the onions in the wine for about a minute or so, scraping up all the browned bits off the pan. Sprinkle 2 tablespoons of flour over the top and stir it into the onions.
- Add the bone broth and stir. There should be no lumps of flour. Add the bay leaf and thyme sprigs. Simmer the soup for 15 to 20 minutes, stirring occasionally.
- While the soup simmers, toast the bread slices and set them aside.
- Turn the oven broiler to high. Take the bay leaf and thyme sprigs out of the soup and discard them. Place 4 (12-ounce) oven-safe soup bowls on a sheet pan. This will make it easier to transfer them to and from the oven.
- Ladle the soup into the bowls. Place the toasted bread on top. Sprinkle the cheese on top, keeping most of it on top of the bread (some will end up in the soup, which is just fine).
- Place the sheet pan under the broiler. Broil the cheese until it’s melted – this will only take a couple of minutes. Serve the soup and enjoy!
Notes
Nutrition Estimate
More Winter Recipes
Happy cooking,
This post was updated from the archives. It was first published in January 2016.
Hi Anne – Thanks so much for asking! I meant to update that in the recipe before publishing — it’s there now, and, yes, you will need a 32 ounce box of broth. I think I still have some holiday fog to shake off 🙂
French onion soup for the win!
Hi Sandra, I’m not sure about that, so if you have the book that came with your slow cooker I would check that. Or maybe check online with the manufacturer — hope that helps!
My son’s favorite soup is French Onion soup. He said this beats any he has had before. Going to be making this soup again. Thanks April.
I’m so glad you guys liked it! Thank you for letting me know 🙂