Caramelized French Onion Soup (Print Version)

Slow-caramelized onions in savory broth topped with cheesy sourdough crostini for a cozy dish.

# Components:

→ For the Soup

01 - 6 large yellow onions, thinly sliced
02 - 3 tablespoons unsalted butter
03 - 1 tablespoon olive oil
04 - 1 teaspoon sugar
05 - 1 teaspoon salt
06 - 1/2 teaspoon freshly ground black pepper
07 - 2 cloves garlic, minced
08 - 2 tablespoons all-purpose flour
09 - 1/2 cup dry white wine
10 - 6 cups beef broth or vegetable broth for vegetarian option
11 - 2 sprigs fresh thyme or 1/2 teaspoon dried
12 - 1 bay leaf
13 - Salt and pepper to taste

→ For the Sourdough Gruyere Crostini

14 - 1 small sourdough baguette, sliced into 1/2-inch rounds
15 - 2 tablespoons olive oil
16 - 1 cup Gruyere cheese, grated
17 - 1/2 cup Parmesan cheese, grated optional

# Directions:

01 - In a large heavy-bottomed pot, melt butter and olive oil over medium heat.
02 - Add sliced onions, sugar, salt, and pepper. Cook, stirring frequently, for 35 to 45 minutes until onions are deep golden and caramelized.
03 - Stir in the garlic and cook for 1 minute.
04 - Sprinkle flour over onions and cook, stirring, for 2 minutes.
05 - Pour in white wine, scraping up any browned bits. Simmer for 2 to 3 minutes to reduce.
06 - Add beef broth, thyme, and bay leaf. Bring to a gentle boil, then reduce heat and simmer uncovered for 25 to 30 minutes. Adjust seasoning with salt and pepper. Discard thyme sprigs and bay leaf.
07 - While soup simmers, preheat oven to 400 degrees Fahrenheit. Arrange baguette slices on a baking sheet, brush with olive oil, and toast for 5 to 7 minutes until golden.
08 - Top toasts with Gruyere and Parmesan if using. Return to oven and bake until cheese is melted and bubbly, 3 to 4 minutes.
09 - Ladle soup into oven-safe bowls, place crostini on top, and optionally broil for 1 to 2 minutes for extra melt. Serve hot.

# Expert Advice:

01 -
  • The slow caramelization process creates a deep, natural sweetness that defines authentic French onion soup.
  • Using sourdough for the crostini adds a wonderful tang and sturdy texture that holds up to the hot broth.
  • It is a versatile dish that works as an impressive starter or a filling main course.
  • The combination of melted Gruyere and savory beef broth is a timeless flavor pairing.
02 -
  • Don't rush the onions; the slow caramelization process is what provides the signature depth of flavor.
  • Scraping the 'fond' after adding the wine is essential for a savory, well-rounded broth.
  • Toast the baguette slices thoroughly before adding the cheese to ensure they don't become soggy too quickly in the soup.
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