How to Make French Onion Soup

How to Make French Onion Soup

French onion soup is a classic dish that hails from France, known for its deep flavors and comforting qualities. This soup combines the sweetness of caramelized onions with the rich taste of beef broth, topped with a crusty piece of bread and melted cheese. Here’s a step-by-step guide to making this delightful soup at home.



  • 6 large onions (yellow or white), thinly sliced
  • 4 tablespoons butter
  • 2 tablespoons olive oil
  • 1 teaspoon sugar
  • 4 cloves garlic, minced
  • 8 cups beef broth
  • 1 cup dry white wine (optional)
  • 2 tablespoons all-purpose flour
  • 1 bay leaf
  • 1 teaspoon dried thyme
  • Salt and pepper to taste
  • 1 baguette, sliced
  • 2 cups grated Gruyère cheese


1. Caramelize the Onions

Start by heating the butter and olive oil in a large pot over medium heat. Add the thinly sliced onions and cook, stirring occasionally, until they become soft and translucent. This should take about 10 minutes.

Once the onions are soft, sprinkle them with the sugar. This will help with the caramelization process. Continue to cook the onions, stirring frequently, until they turn a deep golden brown. This step is crucial as it develops the soup’s signature sweet and savory flavor. It usually takes about 30-40 minutes.

2. Add Garlic and Flour

Add the minced garlic to the caramelized onions and cook for another minute. Sprinkle the flour over the onions and stir well to combine. Cook for another 2-3 minutes to get rid of the raw flour taste. This mixture will help thicken the soup slightly.

3. Add Liquids and Seasonings

Gradually add the beef broth, stirring continuously to avoid any lumps. If using white wine, add it now. Add the bay leaf and thyme. Bring the soup to a boil, then reduce the heat and let it simmer uncovered for about 30 minutes. This will allow the flavors to meld together beautifully. Season with salt and pepper to taste.

4. Prepare the Bread and Cheese

While the soup is simmering, preheat your oven to 400°F (200°C). Arrange the baguette slices on a baking sheet and toast them in the oven until they are golden brown, about 5-7 minutes. You can also rub them with a cut clove of garlic for extra flavor.

Once the bread is toasted, remove it from the oven and set aside. Turn the oven to broil.

5. Assemble and Serve

Once the soup has finished cooking, take out the bay leaf.. Ladle the soup into oven-safe bowls. Place a slice or two of the toasted baguette on top of the soup in each bowl. Generously sprinkle the grated Gruyère cheese over the bread and soup.

Place the bowls on a baking sheet and broil in the oven until the cheese is melted and bubbly, and starts to brown. This should take about 3-5 minutes. Watch it carefully to avoid burning..

Carefully remove the baking sheet from the oven and let the bowls cool for a few minutes before serving. Enjoy your homemade French onion soup!

Tips for the Best French Onion Soup

  • Onions: Yellow onions are traditional, but you can use a mix of yellow and white onions for a more complex flavor.
  • Broth: High-quality beef broth is key to a rich and flavorful soup. If you prefer a lighter version, you can use half beef and half chicken broth.
  • Cheese: Gruyère is the classic choice, but you can also use Swiss or a combination of Swiss and Parmesan for a different twist.

French onion soup is perfect for a cozy night in or as a starter for a special dinner. The process of caramelizing the onions takes some time, but the result is well worth the effort. Bon appétit!