French Onion Soup
See my guide on how to use an Instant Pot.
French Onion Soup, with melt-in-your-mouth caramelized onions, a rich, savory broth and toasted cheesy bread is the ultimate cozy, comforting meal. This simple soup recipe makes the best classic French onion soup.
If anything feels like a hug in a bowl, it is French onion soup. The flavors are rich and inviting, and it’s served with cheesy bread, right in the bowl. So cozy, so comforting, French onion soup is the perfect meal to relax with on a lazy weekend at home.
You can make homemade French onion soup that tastes every bit as good, if not better, than what you might order in a restaurant. While it takes a bit of time to create the layers of flavor found in this traditional onion soup, the steps are easy.
This full-flavored soup gets its rich flavor from caramelized onions (the best!), a good quality beef broth or stock, and toasted cheesy baguette slices. It’s the recipe you’ll turn to when you want a meal that feels fancy but is simple to prepare.
French Onion Soup Ingredients
- Onions: I prefer the flavor of yellow onions in this soup, but you can also use red onions or white onions.
- Butter and Olive Oil: Using unsalted butter allows you to better control the amount of salt. If you use salted butter, just reduce the amount of added salt.
- Garlic: For flavor.
- All-Purpose Flour: To help thicken the broth just a bit.
- White Wine: Adds flavor when deglazing the pan. If you do not want to use wine, you can use additional broth instead.
- Beef Broth or Stock: Use a good quality beef broth or stock, as the flavor of the broth really comes through in the finished dish. I recommend a low sodium broth or stock so that you can control the amount of salt.
- Salt and Pepper: I’ve listed amounts in the recipe card, but I always recommend adding salt and pepper to taste. The amount of salt that you should add will depend on the saltiness of your broth/stock and your tastes.
- Thyme and Bay Leaves: To flavor the soup. Fresh or dried thyme may be used, depending on what you have on hand.
- Baguette Slices and Gruyere Cheese: The best classic French onion soup always has cheesy toasted baguette slices on top!
How to Make French Onion Soup
Here is an overview of how to make this recipe. Find the full recipe with ingredient amounts and instructions below.
First, caramelize the onions. This step brings rich flavor to the soup. Caramelized onions are the best combination of sweet and savory, and making them is easy. You’ll cook the onions in butter and olive oil over medium heat for 25 to 30 minutes. Stir the onions every few minutes to help them cook evenly, and stir more often near the end of the cook time to keep them from burning. The onions are done when they are very soft and browned.
Next, stir in the flour and garlic and cook for just 1 minute to cook off the raw flour and garlic flavors. Deglaze the pot by pouring in the white wine and scraping up any browned bits that are stuck to the bottom of the pot. The browned bits add delicious flavor to the soup.
Add the beef broth, salt, pepper, thyme and bay leaves. Simmer the soup, uncovered, for 30 minutes. Stir occasionally as the soup simmers, and enjoy the delicious aromas that fill your kitchen.
While the soup simmers, toast the baguette slices on a baking sheet in the oven.
Place four oven-safe soup bowls on a heavy rimmed baking sheet. (See below for an alternative if you don’t have oven-safe bowls.) Ladle the soup into the bowls. Top each bowl with two toasted baguette slices, browned side down, and shredded Gruyere cheese. Put the baking sheet in the oven and broil for 2-4 minutes, until the cheese melts and lightly browns.
- Don’t slice the onions too thin or too thick. You don’t want big chunks of onion in the soup, and you don’t want thin stringy pieces. 1/4 inch slices are perfect.
- You can use vegetable broth to make this recipe vegetarian. It will lose some of its rich flavor, but it will still be delicious.
- If you need a substitute for the Gruyere cheese, white cheddar works well. Sometimes I like to add a sprinkle of grated Parmesan on top of the shredded cheese for more flavor.
- If you do not have oven safe bowls, you can make the cheesy toasts on a baking sheet. Toast the bread slices on one side, then flip them over and sprinkle on the cheese. Toast in the oven for a few minutes more to melt and brown the cheese. Ladle the soup into bowls and top with the cheese toasts.
What to Serve with French Onion Soup
I like to serve the soup with extra slices of baguette, for dunking. This soup is hearty and doesn’t need much on the side. A crisp green salad is all that you need to round out the meal. Try my simple green salad, a kale salad or spinach salad. This Lemon Parmesan Kale Salad is bright and fresh and a nice counterpart to the hearty soup.
Make Ahead Instructions
If you’d like to make the soup ahead, you can also toast the baguette slices up to one day ahead of time. Store the toasted bread in an airtight container at room temperature and store the soup in an airtight container in the refrigerator. Right before serving, first warm the soup and then top soup bowls with the toasted baguette slices and cheese and broil as directed in the recipe.
More Favorite Soup Recipes
French Onion Soup
- 3 pounds yellow onions (3-4 large onions)
- 3 tablespoons unsalted butter
- 1 tablespoon extra virgin olive oil
- 2 cloves garlic (minced)
- 2 tablespoons all-purpose flour
- ½ cup dry white wine
- 6 cups low sodium beef broth or stock
- ½ teaspoon salt (or to taste)
- ¼ teaspoon black pepper (or to taste)
- 4 sprigs fresh thyme (or 1 teaspoon dried thyme)
- 2 bay leaves
- 8 slices baguette
- 2 ounces Gruyere cheese (shredded)
- Slice the onions into ¼-inch thick slices.
- Heat the butter and olive oil in a large Dutch oven or other heavy pot over medium heat.
- Once the butter has melted, add the sliced onions to the pot. Cook, stirring every few minutes, until very soft, browned (but not burnt) and caramelized, 25-30 minutes. Near the end of the cook time you will have to stir the onions more often to keep them from burning.
- Add the garlic and flour to the pot and cook, stirring, for 1 minute.
- Pour in the white wine and cook for 1-2 minutes, stirring and scraping up any browned bits from the bottom of the pot.
- Add the beef broth or stock, salt, pepper, thyme sprigs (or dried thyme) and bay leaves. Increase the heat and bring to a simmer, then reduce the heat to a low simmer.
- Cook at a low simmer for 30 minutes, uncovered, stirring occasionally.
- While the soup simmers, preheat the oven to 400° F. Place the baguette slices on a baking sheet. Toast the bread slices in the preheated oven for 5-6 minutes, until golden brown on the edges.
- Taste soup and add additional salt and pepper if needed. Remove the thyme stems and bay leaves and discard.
- Preheat oven broiler to 425° F.
- Place 4 oven-safe soup serving bowls on top of a heavy rimmed baking sheet. Transfer the soup into the serving bowls. Place 2 toasted baguette slices on top of each bowl of soup, browned side down. Sprinkle the shredded Gruyere over the top of the bread slices. (If you do not have oven-safe bowls, you can instead flip the toasted baguette slices over on the baking sheet, sprinkle the cheese on the bread, and broil for 2-4 minutes until the cheese melts and lightly browns. Then serve toasted cheesy bread with the soup.)
- Put the baking sheet with the soup bowls in the oven and broil for 2-4 minutes, until cheese melts and lightly browns. Watch it carefully so as not to burn the cheesy toasts. Serve immediately, garnished with additional fresh thyme if desired. Be careful as the soup bowls will be very hot after they have been in the oven.
- You can use vegetable broth instead of beef broth to make this recipe vegetarian.
- If you need a substitute for the Gruyere cheese, white cheddar works well. You can also add a sprinkle of grated Parmesan on top of the shredded cheese for more flavor.
- To make ahead: Cook the soup and toast the baguette slices up to one day ahead of time. Store the toasted bread in an airtight container at room temperature and store the soup in an airtight container in the refrigerator. Right before serving, first warm the soup and then top soup bowls with the toasted baguette slices and cheese and broil as directed in the recipe.
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