Description

Get ready to fall in love with the rich, cheesy comfort of this French Onion Casserole—a heartwarming twist on the beloved French onion soup. Imagine layers of golden caramelized onions, toasted bread, and bubbling, melty cheese baked to perfection. This easy recipe turns classic flavors into a satisfying main dish or decadent side that’s perfect for cold nights, cozy dinners, or impressive potluck contributions.

Ingredients

4 large yellow onions, thinly sliced

3 tablespoons unsalted butter

1 tablespoon olive oil

2 teaspoons sugar

1 teaspoon salt

1/2 teaspoon black pepper

1 teaspoon fresh thyme leaves (or 1/2 tsp dried)

2 cloves garlic, minced

1/2 cup dry white wine (optional)

2 cups beef broth

1 tablespoon Worcestershire sauce

6 slices thick French bread, toasted

2 cups shredded Gruyère cheese

1 cup shredded mozzarella cheese

1/4 cup grated Parmesan cheese

Instructions

In a large skillet, heat butter and olive oil over medium. Add onions, sugar, salt, and pepper. Cook for 25–30 minutes, stirring occasionally, until caramelized.
Add garlic and thyme; cook for 1 more minute. Deglaze with wine if using, scraping the pan. Simmer 2–3 minutes.
Stir in broth and Worcestershire. Simmer for 5–7 minutes. Remove from heat.
Toast bread slices in the oven at 375°F (190°C) until crisp, about 5 minutes per side.
Grease a casserole dish. Layer half the bread, half the onion mixture, and half the cheese. Repeat layers.
Cover with foil and bake for 20 minutes. Uncover and bake another 10–15 minutes until bubbly and golden.
Broil for 1–2 minutes for extra browning if desired. Garnish with fresh thyme. Serve warm.

Prep Time: 15 minutes
Cook Time: 50 minutes
Category: Casserole