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french onion casserole

french onion casserole

This French onion casserole brings the rich, savory flavors of classic French onion soup into a comforting and hearty dish. Topped with melted cheese and crispy bread, this casserole is perfect for a cozy dinner or as a side dish for gatherings.
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Prep Time 15 minutes
Cook Time 45 minutes
Total Time 1 hour
Course Main Course
Cuisine French Cuisine
Servings 4 People
Calories 320 kcal

Equipment

  • 1 large skillet
  • 1 casserole dish (2-quart size)
  • 1 cutting board
  • 1 set measuring cups and spoons
  • 1 oven

Ingredients
  

  • 4 large onions, thinly sliced
  • 3 tablespoons unsalted butter
  • 1 tablespoon olive oil
  • 1 teaspoon salt
  • 1 teaspoon sugar
  • 4 cloves garlic, minced
  • 1 tablespoon fresh thyme leaves or 1 teaspoon dried thyme
  • ¼ cup all-purpose flour
  • 4 cups beef broth
  • 1 cup grated Gruyère cheese plus more for topping
  • 1 cup grated Swiss cheese
  • 6 cups cubed French bread
  • Fresh parsley for garnish optional

Instructions
 

  • Preheat the oven to 350°F (175°C).
  • In a large skillet, melt the butter and olive oil over medium heat. Add the sliced onions, salt, and sugar. Cook, stirring occasionally, until the onions are caramelized and golden brown, about 20-25 minutes.
  • Stir in the minced garlic and thyme, cooking for another 2-3 minutes until fragrant.
  • Sprinkle the flour over the caramelized onions and stir to combine, cooking for an additional minute.
  • Gradually pour in the beef broth, stirring continuously to avoid lumps. Bring the mixture to a simmer and cook for about 5 minutes until slightly thickened.
  • Remove the skillet from heat and stir in the Gruyère and Swiss cheeses until melted and combined.
  • In a greased casserole dish, layer half of the cubed French bread on the bottom. Pour half of the onion mixture over the bread. Repeat the layers with the remaining bread and onion mixture.
  • Top the casserole with additional Gruyère cheese to taste.
  • Bake in the preheated oven for 25-30 minutes, or until the cheese is bubbly and golden brown on top.
  • Remove from the oven and let it cool for a few minutes before garnishing with fresh parsley, if desired. Serve warm.

Notes

For a vegetarian version, substitute vegetable broth for beef broth.
You can also add cooked ground beef or sausage for a heartier dish.
Leftovers can be stored in the refrigerator for up to 3 days and reheated in the oven or microwave.