Jul 14 2026
Restaurants›Petit Louis Bistro›Soupe À L'oignon Gratinée Recipe

Soupe À L'oignon Gratinée Recipe

Inspired by Petit Louis Bistro
Time1h 15m
Serves6

Louis' Famous Onion Soup

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Ingredients

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Soup Base

Topping

Method

Soup Preparation

  1. 1

    Sauté the Onions

    In a large pot, melt the butter and olive oil over medium heat. Add the sliced yellow onions and stir to coat them in the fat. Cook for about 30-40 minutes, stirring occasionally, until the onions are caramelized and golden brown.

  2. 2

    Add Garlic and Herbs

    Once the onions are caramelized, add minced garlic, thyme, and the bay leaf. Cook for an additional 2-3 minutes until the garlic is fragrant.

  3. 3

    Add Broth and Seasoning

    Pour in the beef broth and add salt and black pepper. Bring the mixture to a simmer and let it cook for 20-30 minutes to allow the flavors to meld. Remove the bay leaf before serving.

Topping and Broiling

  1. 4

    Prepare the Bread

    While the soup is simmering, preheat your oven to 350°F (175°C). Slice the baguette or French bread into 1-inch thick slices and place them on a baking sheet.

  2. 5

    Toast the Bread

    Toast the bread slices in the preheated oven for about 10-15 minutes until they are lightly golden and crisp.

  3. 6

    Assemble the Soup

    Ladle the hot soup into oven-safe bowls, place a toasted slice of bread on top of each bowl, and generously sprinkle with Gruyère and Parmesan cheese.

  4. 7

    Broil the Soup

    Place the assembled bowls under the broiler for 3-5 minutes, or until the cheese is bubbly and golden brown. Keep an eye on them to prevent burning.

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