← BlogJune 28, 2026

How to Make the Perfect French Onion Soup with Gruyere Croutons

French · Medium · 90 min · 4 servings

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This deeply savory French onion soup is built on a foundation of slowly caramelized onions simmered in rich beef broth with a splash of white wine. It is finished with toasted baguette slices blanketed in bubbling melted gruyere cheese.

Why this recipe works

This French Onion Soup with Gruyere Croutons recipe has been crafted to deliver restaurant-quality results in your home kitchen. At just 90 minutes from start to finish, it fits perfectly into a busy schedule without sacrificing flavor. Each serving comes in at 490 calories with 18g of protein, making it a balanced choice for any meal.

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What you will need

This recipe uses 6 simple ingredients that you can find at any grocery store:

  • 4 large yellow onions thinly sliced
  • 4 cups beef broth
  • 0.5 cup dry white wine
  • 8 slices baguette toasted
  • 1.5 cups shredded gruyere cheese
  • 2 tbsp unsalted butter

Step by step instructions

Step 1: Caramelize the Onions

Melt the butter in a large heavy-bottomed pot over medium-low heat. Add all the sliced onions with a pinch of salt. Cook slowly, stirring every 5 minutes, for 50 to 60 minutes until the onions are deeply golden brown and jammy. Do not rush this process.

Step 2: Deglaze and Simmer

Pour the white wine into the pot with the caramelized onions and scrape up any browned bits from the bottom. Let the wine cook off for 2 minutes, then add the beef broth. Bring to a simmer and cook for 15 minutes to develop flavor.

Step 3: Prepare the Croutons

While the soup simmers, arrange the baguette slices on a baking sheet and toast under the broiler for 2 minutes per side until golden and crisp. Top each slice generously with the shredded gruyere cheese.

Step 4: Broil and Serve

Ladle the hot soup into oven-safe bowls placed on a baking sheet. Float the cheese-topped croutons on the surface of each bowl. Place under the broiler for 3 to 4 minutes until the cheese is melted and bubbling with golden spots.

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Easy substitutions

Missing an ingredient? Here are some swaps that work perfectly:

  • gruyere cheese → Swiss or Emmental cheese for a similar nutty and melty result
  • dry white wine → apple cider or additional beef broth for an alcohol-free version

Common mistakes to avoid

Watch out for these pitfalls that can affect your results:

  • Caramelizing the onions on high heat which burns them instead of slowly sweetening them
  • Using a low-quality or overly salty beef broth which makes the final soup unpleasantly salty

Nutrition facts

Per serving: 490 calories, 18g protein, 42g carbs, 26g fat, 4g fiber.

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