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–+ servings
savory onion soup bake

French Onion Soup Casserole

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Prep Time 15 minutes
Cook Time 1 hour
Resting Time 5 minutes
Total Time 1 hour 20 minutes
Course Main
Cuisine French
Servings 6 servings

Equipment

  • 1 large skillet
  • 1 Baking dish
  • 1 Whisk
  • 1 Knife
  • 1 Cutting board
  • 1 Mixing bowl
  • 1 Spatula

Ingredients
  

  • 3 tablespoon unsalted butter
  • 4 large onions thinly sliced
  • 1 teaspoon salt
  • 1 teaspoon sugar
  • 1 tablespoon all-purpose flour
  • 2 cup beef broth
  • 1 cup dry white wine
  • 1 teaspoon fresh thyme leaves
  • 6 slice baguette toasted
  • 2 cup Gruyère cheese shredded
  • 1/4 cup fresh parsley chopped

Instructions
 

  • Melt butter in a large skillet over medium heat.
  • Add sliced onions, salt, and sugar to the skillet and cook until the onions are caramelized, about 25 minutes.
  • Stir in flour and cook for 1 minute.
  • Gradually whisk in beef broth and wine, bringing the mixture to a simmer.
  • Add thyme leaves and continue to simmer for an additional 10 minutes to thicken slightly.
  • Preheat the oven to 375°F (190°C).
  • Pour the onion mixture into a baking dish.
  • Arrange toasted baguette slices on top of the mixture.
  • Sprinkle shredded Gruyère cheese evenly over the bread.
  • Bake in the preheated oven until the cheese is melted and bubbly, about 20 minutes.
  • Allow the casserole to rest for 5 minutes before serving.
  • Garnish with chopped parsley before serving.

Notes

For a richer flavor, consider using a combination of sweet and yellow onions. If you prefer a crunchier texture, broil the casserole for an additional 2-3 minutes after baking. Make sure to toast the baguette slices well to prevent them from becoming too soggy, and for a deeper taste, use a good quality beef broth.
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