# Ingredients:
→ Onions
01 - 6 large yellow onions, thinly sliced
02 - 2 tablespoons unsalted butter
03 - 1 tablespoon olive oil
→ Broth
04 - 6 cups beef broth
05 - 1/2 cup dry white wine, optional
→ Flavorings
06 - 2 cloves garlic, minced
07 - 1 teaspoon sugar
08 - 1 teaspoon salt
09 - 1/2 teaspoon freshly ground black pepper
10 - 2 sprigs fresh thyme or 1/2 teaspoon dried thyme
11 - 1 bay leaf
→ Topping
12 - 4 slices crusty French bread, approximately 1 inch thick
13 - 2 cups grated Gruyère cheese
# Directions:
01 - In a large heavy-bottomed pot, melt butter with olive oil over medium heat. Add sliced onions and cook, stirring occasionally, until softened, approximately 15 minutes.
02 - Sprinkle onions with sugar and salt. Continue cooking, stirring frequently, until deeply golden and caramelized, 30 to 40 minutes.
03 - Add minced garlic and cook for 1 minute, stirring constantly.
04 - Pour in white wine if using and scrape up browned bits from bottom of pot. Simmer for 2 to 3 minutes.
05 - Add beef broth, thyme, bay leaf, and black pepper. Bring to boil, then reduce heat and simmer uncovered for 30 minutes. Remove and discard thyme sprigs and bay leaf.
06 - Preheat broiler. Arrange bread slices on baking sheet and toast under broiler until lightly golden on both sides.
07 - Ladle hot soup into oven-safe bowls. Top each with one slice of toasted bread and a generous handful of Gruyère cheese.
08 - Place bowls under broiler until cheese is melted and bubbling, 2 to 3 minutes. Serve immediately.