French Onion Soup

Warm, cozy, and flavorful, this French onion soup is prepared with beef stock and caramelized onions. Top with croutons covered in melty Gruyere and Parmesan cheese.

French Onion Soup
Elise Bauer

Is there anything more comforting on a chilly day than a hot bowl of French onion soup? Especially with a thick slice of toasted bread loaded with melty Gruyere cheese and lots of caramelized onions.

Video! How to Make French Onion Soup

2:13

French Onion Soup

How to Make the Best French Onion Soup

There are two essential components of a good French onion soup.

The first is the stock. Your soup will only be as good as the stock you are using. This soup traditionally is made with beef stock, though sometimes a good beef stock can be hard to come by and expensive to make.

If you use boxed stock, taste it first! If you don't like the taste, don't use it. (If you cook a lot of beef or beef roasts, save the scraps and freeze them to make a stock with later.)

French Onion Soup
Elise Bauer

The second most important element is to properly caramelize the onions. Caramelizing the amount of onions needed in this recipe will take at least 40 minutes. Caramelizing is a chemical process that occurs when the sugars in the onions reach a certain temperature.

This only happens after a long cooking time (the addition of a little extra sugar will help). The more caramelized, the deeper the color of the onions and the more flavor you'll get from them.

Alternatives to Wine

The recipe calls for dry vermouth or white wine as well as brandy, which is optional. If you prefer not to use any alcohol, many readers who made the recipe mentioned in the comments that they omit it altogether and it's still delicious.

Others mentioned adding some Worcestershire sauce at the end to give it an additional depth of flavor. If you omit the alcohol, you may want to add a tablespoon or so of Worcestershire, but it's not necessary.

If you do choose to omit the alcohol, use a half cup of the beef broth to deglaze the pan as instructed in Step 2 before adding the remaining stock in Step 3.

The Best Cheese to Use for French Onion Soup

Gruyere and Parmesan are the classics for French Onion Soup. However, if you don't have them, try these alternatives.

  • Gouda
  • Swiss
  • Fontina
  • Mozzarella

How to Store and Reheat This Dish

Store the soup—without the croutons—in an airtight container in the refrigerator for 3 to 4 days. Reheat on the stovetop until just heated through. The croutons are best when made fresh.

How to Freeze French Onion Soup

This soup—without the croutons—freezes well. Freeze soup that has come to room temperature (or refrigerator temperature) in portion sizes in freezer safe containers or zipper bags for up to 3 months. Defrost in the refrigerator and reheat on the stovetop until just heated through. Make fresh croutons for topping.

More Warn and Cozy Soup Recipes to Try!

From the Editors Of Simply Recipes

French Onion Soup

Prep Time 10 mins
Cook Time 70 mins
Total Time 80 mins
Servings 4 to 6 servings

Much of the success of this soup depends on the stock that you are using, and stock varies tremendously in its taste. Depending on your stock, you may need to bump up the flavor with some beef bouillon (we recommend Better Than Bouillon brand).

Taste the soup before putting it in the oven, and if it needs more seasoning, don't be afraid to add more!

Ingredients

  • 6 large red or yellow onions (about 3 pounds), peeled and thinly sliced root to stem (see How to Slice an Onion), about 10 cups of sliced onions total

  • 4 tablespoons extra virgin olive oil

  • 2 tablespoons butter

  • 1 teaspoon sugar

  • Kosher salt

  • 2 cloves garlic, minced

  • 8 cups beef stock, chicken stock, or a combination of the two (traditionally the soup is made with beef stock)

  • 1/2 cup dry vermouth or dry white wine

  • 2 bay leaves

  • 1 tablespoon fresh thyme leaves (can also use a few sprigs of fresh thyme) OR 1/2 teaspoon dried thyme (more to taste)

  • 1/2 teaspoon freshly ground black pepper

  • 2 tablespoons brandy (optional)

  • 8 slices (1-inch thick) French bread or baguette

  • 1 1/2 cups grated Swiss Gruyere

  • Sprinkling of Parmesan

Method

  1. Caramelize the onions:

    In a 5 to 6 quart thick-bottomed pot, heat 3 tablespoons of olive oil on medium heat. Add the onions and toss to coat with the olive oil.

    Cook the onions, stirring often, until they have softened, about 15 to 20 minutes.

    Increase the heat to medium high. Add the remaining tablespoon of olive oil and the butter and cook, stirring often, until the onions start to brown, about 15 more minutes.

    french-onion-soup-method-1
    Elise Bauer

    Sprinkle with sugar (to help with the caramelization) and 1 teaspoon of salt. Continue to cook until the onions are well browned, about 10 to 15 more minutes.

    french-onion-soup-method-2
    Elise Bauer

    Add the minced garlic and cook for a minute more.

  2. Deglaze the pot with vermouth or wine:

    Add the wine or vermouth to the pot and scrape up the browned bits on the bottom and sides of the pot, deglazing the pot as you go.

    french-onion-soup-method-3
    Elise Bauer
  3. Add the stock, bay leaves, and thyme:

    Add the stock, bay leaves, and thyme. Bring to a simmer, cover the pot and lower the heat to maintain a low simmer. Cook for about 30 minutes.

    french-onion-soup-method-4
    Elise Bauer
    french-onion-soup-method-7
    Elise Bauer

    Season to taste with more salt and add freshly ground black pepper. Discard the bay leaves. Add brandy if using.

  4. Toast the French bread slices:

    While the soup is simmering, line a sheet pan with parchment paper or foil and preheat the oven to 450°F with a rack in the upper third of the oven.

    Brush both sides of the French bread or baguette slices lightly with olive oil (you'll end up using about a tablespoon and a half of olive oil for this).

    Put in the oven and toast until lightly browned, about 5 to 7 minutes. Remove from oven.

    french-onion-soup-method-5
    Elise Bauer
    french-onion-soup-method-6
    Elise Bauer

    Turn the toasts over and sprinkle with the grated Gruyere cheese and Parmesan. Return to oven when it's close to serving time and bake until the cheese is bubbly and lightly browned.

  5. Serve:

    To serve, ladle soup into a bowl and transfer one cheesy toast onto the top of each bowl of soup.

    Alternatively, you can use individual oven-proof bowls or one large casserole dish. Ladle the soup into the bowls or casserole dish. Cover with the toast and sprinkle with cheese. Put into the broiler for 10 minutes at 350° F, or until the cheese bubbles and is slightly browned.

French Onion Soup
Elise Bauer
Nutrition Facts (per serving)
699 Calories
26g Fat
84g Carbs
30g Protein
Show Full Nutrition Label Hide Full Nutrition Label
×
Nutrition Facts
Servings: 4 to 6
Amount per serving
Calories 699
% Daily Value*
Total Fat 26g 33%
Saturated Fat 10g 50%
Cholesterol 43mg 14%
Sodium 1727mg 75%
Total Carbohydrate 84g 30%
Dietary Fiber 5g 16%
Total Sugars 14g
Protein 30g
Vitamin C 8mg 38%
Calcium 424mg 33%
Iron 6mg 34%
Potassium 1000mg 21%
*The % Daily Value (DV) tells you how much a nutrient in a food serving contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.
Nutrition information is calculated using an ingredient database and should be considered an estimate. In cases where multiple ingredient alternatives are given, the first listed is calculated for nutrition. Garnishes and optional ingredients are not included.