Onion Soup Gratiné Recipe

Soup Preparation

1. 1

   Caramelize the Onions

   In a large pot, melt 2 tablespoons of butter over medium heat. Add the sliced onions and cook, stirring occasionally, until they are deep golden brown and caramelized, about 25-30 minutes.

2. 2

   Add Leek and Cognac

   Add the chopped leek to the pot and cook for an additional 5 minutes until softened. Pour in the cognac and scrape the bottom of the pot to deglaze, letting it cook for 2 minutes.

3. 3

   Add Broth and Seasonings

   Add the beef broth, bay leaf, thyme, salt, and pepper. Bring the soup to a simmer and let it cook for 20 minutes.

4. 4

   Prepare Croutons

   While the soup simmers, preheat the oven to 375°F (190°C). Cut a baguette into slices, brush them with olive oil, and bake until golden brown, about 10-15 minutes.

5. 5

   Serve the Soup

   Remove the bay leaf from the soup. Ladle the soup into oven-safe bowls, top each with a crouton, and generously sprinkle with gruyère cheese.

6. 6

   Gratiné the Soup

   Place the bowls under the broiler in the oven for 2-3 minutes until the cheese is bubbly and golden. Watch closely to prevent burning.