# What You'll Need:
→ Onions
01 - 5 large yellow onions, thinly sliced
→ Aromatics
02 - 3 tablespoons unsalted butter
03 - 2 tablespoons olive oil
04 - 2 garlic cloves, minced
05 - 1 teaspoon sugar
→ Broth & Flavorings
06 - 8 cups beef broth
07 - 1/2 cup dry white wine
08 - 2 teaspoons fresh thyme leaves
09 - 2 bay leaves
10 - 1 tablespoon Worcestershire sauce
11 - Salt and freshly ground black pepper to taste
→ Topping
12 - 1 baguette, sliced into 1/2-inch thick rounds
13 - 2 cups Gruyère cheese, grated
14 - 1/2 cup Parmesan cheese, grated
# How To Make It:
01 - In a large Dutch oven over medium heat, melt the butter with olive oil. Add the sliced onions and sugar. Cook, stirring frequently, until onions are very soft and deeply caramelized, about 40 to 45 minutes.
02 - Add the minced garlic and cook for 1 minute until fragrant.
03 - Pour in the wine, scraping up any browned bits from the bottom of the Dutch oven. Simmer for 2 to 3 minutes until slightly reduced.
04 - Add the broth, thyme, bay leaves, and Worcestershire sauce. Bring to a simmer, reduce heat, and cook uncovered for 20 to 30 minutes. Season with salt and pepper to taste. Remove bay leaves.
05 - While soup simmers, preheat oven broiler. Arrange baguette slices on a baking sheet and toast under the broiler until golden, about 1 to 2 minutes per side.
06 - Ladle soup into oven-safe bowls. Top each with a toasted baguette slice and a generous handful of Gruyère cheese and Parmesan cheese.
07 - Place bowls on a baking sheet and broil until cheese is melted and bubbling, 2 to 4 minutes.
08 - Remove from broiler and serve immediately, garnished with extra thyme if desired.
