Go Back

French Onion Soup

French onion soup made with slow-caramelized onions for a deeply golden, jammy broth and a classic melted Gruyère cheese crust. Ladled into oven-safe crocks and broiled until bubbling and browned.
Print Recipe Pin Recipe
Prep Time 15 minutes
Cook Time 1 hour 30 minutes
Total Time 1 hour 45 minutes
Servings: 6 servings
Course: Main Dish
Cuisine: French
Calories: 595
Ingredients Equipment Method Notes

Ingredients
  

Onions
  • 4 lb yellow onions Thinly sliced for even caramelization.
Fats & aromatics
  • 4 tbsp unsalted butter
  • 1 tbsp olive oil
Wine for deglazing
  • 1 cup dry white wine or sherry
Broth & herbs
  • 6 cup beef broth
  • 2 sprigs fresh thyme Use 2 sprigs (remove after simmer).
  • 1 bay leaf Remove after simmer.
  • 1 tsp Worcestershire sauce
Bread topping
  • 6 baguette or French bread Slice and toast, then float on top of the soup in crocks.
Cheese topping
  • 2 cup Gruyere cheese, shredded
  • 0.5 cup parmesan Grated.
Seasoning
  • 0.5 Salt and pepper to taste Season the soup after simmering to taste.

Equipment

  • 1 Dutch oven

Method
 

Caramelize the onions
  1. Melt the butter with the olive oil in a large heavy pot over medium heat, then add the onions and 1/2 teaspoon salt. Stir to coat the onions evenly and start softening them.
  2. Cook the onions for 60-70 minutes over medium heat, stirring every 10-15 minutes until deeply golden, jammy, and caramelized. Watch for even browning at the bottom and along the edges.
Build the soup
  1. Deglaze with the wine (or sherry) and cook for 3 minutes, scraping up all browned bits from the pot. Let the alcohol reduce so the flavor turns mellow.
  2. Add the beef broth, fresh thyme, bay leaf, and Worcestershire sauce, then simmer for 20 minutes. Keep the surface at a gentle simmer and stir occasionally.
  3. Remove the thyme and bay leaf, then season with salt and pepper to taste. Taste the broth and adjust until balanced.
Broil the cheesy topping
  1. Ladle the hot soup into oven-safe crocks, then float the toasted baguette slices on top. Arrange the bread so it sits under the cheese layer.
  2. Pile the Gruyère and parmesan over the bread, then broil for 3-4 minutes until melted and bubbly. Look for a golden-brown top before serving.

Notes

For best flavor, caramelize until the onions are truly jammy and deep golden—stirring every 10-15 minutes prevents scorching. Store leftovers covered in the refrigerator up to 3-4 days; reheat gently on the stovetop or in the oven and broil the cheese fresh if possible. Freezing is not ideal for the bread topping, but you can freeze the soup base (no bread/cheese) up to 2 months. For a lighter option, use half the butter and replace part of the Gruyère with reduced-fat cheese while keeping the same broiling time.