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French Onion Soup

A comforting classic, this French Onion Soup features deeply caramelized onions in a rich broth, topped with crusty bread and melted Gruyère cheese.
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Prep Time 15 minutes
Cook Time 1 hour 15 minutes
Total Time 1 hour 30 minutes
Servings: 6 servings
Course: Appetizer, Dinner
Cuisine: French
Calories: 290
Ingredients Method Notes

Ingredients
  

For the Soup
  • 3 pounds yellow onions (about 6 large), thinly sliced
  • 3 tablespoons unsalted butter
  • 1 tablespoon olive oil
  • 1 teaspoon sugar
  • 2 cloves garlic, minced
  • 1/2 cup dry white wine (or use additional broth)
  • 6 cups beef stock or broth
  • 4-5 sprigs fresh thyme
  • Salt and black pepper to taste
For Topping
  • 1 baguette sliced 1-inch thick
  • 2 cups grated Gruyère cheese
  • 1/2 cup grated Parmesan cheese
  • Fresh thyme for garnish (optional)

Method
 

Preparation
  1. Peel the onions and cut in half through the root end. Lay flat and slice thinly into half-moons.
  2. Melt butter with olive oil in a large heavy-bottomed pot over medium heat.
  3. Add all sliced onions to the pot, stir to coat in butter, and add sugar and a good pinch of salt.
Caramelization
  1. Cook onions over medium heat, stirring every 3-4 minutes until translucent, about 15 minutes.
  2. Continue cooking, stirring every 5 minutes until they turn golden and develop fond, about 20-25 minutes.
  3. In the final 15-20 minutes, stir more frequently and watch carefully until deeply caramelized, about 50-60 minutes total.
Building the Soup
  1. Add minced garlic and cook for 30 seconds, then deglaze with white wine.
  2. Add beef stock, bay leaves, thyme, and bring to a boil. Reduce to simmer for 20-25 minutes.
  3. Season with salt and pepper, and remove bay leaves and thyme sprigs before serving.
Preparing the Bread
  1. Preheat the oven to 400°F (200°C). Arrange baguette slices on a baking sheet and toast for 5-7 minutes until golden.
  2. Flip slices and toast the other side for an additional 3-4 minutes until crispy.
Assembling and Broiling
  1. Ladle the hot soup into oven-safe bowls or crocks, filling each about 3/4 full.
  2. Float 1-2 toasted bread slices on each bowl, then pile grated Gruyère generously on top.
  3. Sprinkle Parmesan on top and broil for 3-5 minutes until cheese is bubbling and browned.

Notes

Store leftovers without bread and cheese in an airtight container for up to 5 days. The flavor improves after a day.