# Components:
→ Onions
01 - 4 large yellow onions, thinly sliced
→ Fats
02 - 3 tablespoons unsalted butter
03 - 1 tablespoon olive oil
→ Broth and Seasoning
04 - 8 cups beef broth or vegetable broth
05 - 1/2 cup dry white wine (optional)
06 - 2 teaspoons fresh thyme leaves or 1 teaspoon dried thyme
07 - 2 bay leaves
08 - Salt and freshly ground black pepper, to taste
→ Bread and Cheese
09 - 1 baguette, sliced into 1/2-inch rounds
10 - 2 cups grated Gruyère cheese
# Preparation Steps:
01 - In a large heavy-bottomed pot over medium heat, melt butter and olive oil. Add the sliced onions and cook, stirring regularly, until very soft and deeply caramelized, approximately 35-40 minutes.
02 - Incorporate thyme and bay leaves. If using, pour in white wine and deglaze, scraping any browned residue from the pot base.
03 - Add beef broth and bring the mixture to a simmer. Allow to cook for 20 minutes. Season with salt and freshly ground black pepper to preference. Remove the bay leaves after simmering.
04 - While the soup simmers, preheat broiler. Place baguette slices onto a baking sheet and toast until golden brown on each side.
05 - Ladle the soup into oven-safe bowls. Top each portion with 1-2 toasted baguette rounds, then sprinkle generously with Gruyère cheese.
06 - Place bowls under the broiler until the cheese is melted and bubbly, about 2-3 minutes. Serve immediately.
