Jul 14 2026
RestaurantsMahogany Prime SteakhouseFrench Onion Au Gratin Recipe

French Onion Au Gratin Recipe

Time1h 30m
Serves4

Make French Onion Au Gratin Recipe in just 1h 30m. Get the full recipe with step-by-step instructions at pekinthechef.com.

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Ingredients

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Main Ingredients

Method

Preparation Steps

  1. 1

    Prepare the Onions

    Slice the yellow onions into thin rings. They should be uniform in thickness to ensure even cooking.

  2. 2

    Sauté the Onions

    In a large pot, melt the butter over medium heat. Add the sliced onions and sauté for about 25-30 minutes, stirring frequently until they are caramelized and golden brown.

  3. 3

    Add Liquids and Seasonings

    Pour in the beef broth and dry white wine. Add the thyme, bay leaves, salt, and black pepper. Stir well to combine and bring to a simmer.

  4. 4

    Simmer the Soup

    Reduce the heat to low and let the mixture simmer for about 30 minutes to allow the flavors to develop. Stir occasionally.

  5. 5

    Prepare the Baguette

    While the soup is simmering, slice the French baguette into thick slices and toast them in the oven until golden brown.

  6. 6

    Assemble the Au Gratin

    Preheat your oven to 350°F (175°C). Ladle the soup into oven-safe bowls, place a slice of toasted baguette on top of each bowl, and generously sprinkle with Gruyere and Parmesan cheese.

  7. 7

    Bake

    Place the bowls on a baking sheet and bake in the preheated oven for about 15-20 minutes, or until the cheese is bubbly and golden brown.

  8. 8

    Serve

    Remove the bowls from the oven carefully. Let them cool slightly before serving. Enjoy your French Onion Au Gratin!

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