French Onion Soup Casserole

INGREDIENTS

• 1/4 cup unsalted butter
• 3 lbs Vidalia onions, thinly sliced (about 5 medium)
• 2 teaspoons Kosher salt
• 1/2 teaspoon black pepper
• 3 sprigs thyme, plus more for topping
• 2 bay leaves
• 1 baguette, thinly sliced
• 1/3 cup all-purpose flour
• 3 cups beef broth
• 1/2 cup sherry
• 2 cups Gruyere cheese, grated

PREPARATION

1. Preheat oven to 350°F.
2. Melt butter in a large Dutch oven or heavy-bottomed pot over medium-low heat. Once melted, add onions, salt, pepper, thyme, and bay leaves and cook until onions are golden brown, stirring often until golden brown, about 40-50 minutes.
3. Arrange baguette slices on a baking sheet and bake until lightly toasted, 10-12 minutes. Remove from oven and set aside.
4. Remove thyme sprigs and bay leaves from onion mixture. Stir in flour and stir constantly for 2 minutes. Stir in broth and sherry and bring to a boil. Let bubble until slightly thickened, stirring constantly, about 5 minutes.
5. Layer half of the baguette slices in a 9×13-inch baking dish. Spoon onion mixture over the top. Top with remaining baguette slices and sprinkle with cheese.
6. Cover dish tightly with foil and bake 30 minutes. Remove foil, and broil on high until cheese is golden brown and bubbly, 3-5 minutes. Sprinkle with thyme leaves and serve. Enjoy!