Ingredients:

  • 4 large yellow onions (about 1.5 kg)
  • 4 tablespoons unsalted butter (55 g)
  • 1 tablespoon olive oil (15 ml)
  • 1 teaspoon sugar (5 g)
  • 1 teaspoon salt (5 g)
  • 4 cups beef broth (946 ml)
  • 1 cup dry white wine (240 ml)
  • 2 teaspoons fresh thyme (or 1 teaspoon dried)
  • 1 bay leaf
  • 8 slices of baguette (about 200 g)
  • 1 ½ cups Gruyère cheese, grated (150 g)
  • Freshly cracked black pepper, to taste

Instructions:

  1. Peel and slice the onions thinly.
  2. Melt butter and olive oil in a pot over medium heat. Add onions, salt, and sugar; cook until soft and caramelized, stirring frequently. Aim for a deep golden color (about 30-40 minutes).
  3. Pour in white wine and stir to deglaze the pot, scraping up any flavorful bits. Let simmer for 5-7 minutes.
  4. Stir in beef broth, thyme, and bay leaf; bring to a simmer. Cook for another 15 minutes to develop the flavors.
  5. Toast the baguette slices until golden.
  6. Ladle soup into broiler-safe bowls; top each with a toasted baguette slice. Generously sprinkle Gruyère cheese over the top.
  7. Place bowls under the broiler until cheese is melted and bubbling (2-3 minutes).
  8. Carefully remove from the oven and let cool slightly before serving.