Rich, comforting French classic with deeply caramelized onions in savory broth, topped with toasted bread and golden bubbly Gruyère.
# What You'll Need:
→ Onions
01 - 3 large yellow onions, thinly sliced
02 - 1 tablespoon unsalted butter
03 - 1 tablespoon olive oil
→ Soup Base
04 - 2 cloves garlic, minced
05 - 1 teaspoon sugar
06 - 1/2 teaspoon salt
07 - 1/4 teaspoon freshly ground black pepper
08 - 2 tablespoons all-purpose flour
09 - 1/2 cup dry white wine
10 - 5 cups beef or vegetable stock
11 - 2 sprigs fresh thyme
12 - 1 bay leaf
→ Topping
13 - 4 slices French baguette, about 1 inch thick
14 - 1 tablespoon olive oil for bread
15 - 1 cup Gruyère cheese, grated
# How To Make It:
01 - Heat butter and olive oil in a large pot over medium heat. Add sliced onions and stir to coat. Cook, stirring frequently, until deeply caramelized, approximately 35-40 minutes. Add sugar and salt halfway through cooking to enhance caramelization.
02 - Add minced garlic and cook for 1 minute until fragrant.
03 - Sprinkle flour into the pot and cook while stirring for 2 minutes to create a light roux.
04 - Pour in white wine while scraping the bottom of the pot to release all caramelized bits and fond.
05 - Pour in stock and add thyme sprigs and bay leaf. Bring to a simmer, then reduce heat and cook uncovered for 20-25 minutes. Remove thyme and bay leaf. Season with pepper and additional salt to taste.
06 - Preheat oven broiler. Arrange baguette slices on a baking sheet, brush both sides with olive oil, and toast under the broiler until golden, approximately 1-2 minutes per side.
07 - Ladle hot soup into oven-safe bowls. Top each with a toasted baguette slice and cover generously with grated Gruyère cheese.
08 - Place bowls on a baking sheet and broil for 2-3 minutes until cheese is melted, bubbly, and golden brown. Serve immediately.