Ingredients:

  • 6 large yellow onions (approx. 1.5kg), thinly sliced
  • 3 tbsp unsalted butter
  • 1 tbsp extra virgin olive oil
  • 1 tsp sea salt
  • 1/2 tsp granulated sugar
  • 1 tbsp all-purpose flour
  • 1/2 cup dry white wine
  • 6 cups high-quality beef stock
  • 2 tbsp brandy
  • 2 sprigs fresh thyme
  • 1 dried bay leaf
  • 1 French baguette, cut into 1-inch thick slices
  • 2 cups Gruyere cheese, freshly grated
  • 1/4 cup Parmigiano-Reggiano, finely grated
  • 1 clove garlic, peeled

Instructions:

  1. In a large heavy-bottomed pot or Dutch oven over medium heat, melt the 3 tbsp butter with 1 tbsp olive oil until the butter foam subsides and sizzles.
  2. Toss in the 1.5kg sliced onions and coat them in the fat. Cook for 15 minutes, stirring occasionally, until they are soft and translucent.
  3. Stir in the 1 tsp salt and 1/2 tsp sugar. Lower the heat and cook for 40 minutes, stirring every 5 minutes until the onions are a deep, rich brown.
  4. Sprinkle the 1 tbsp flour over the onions and cook for 2 minutes until the raw flour smell disappears.
  5. Deglaze the pan with 1/2 cup white wine, scraping all the brown bits off the bottom until the liquid has mostly evaporated.
  6. Add the 6 cups beef stock, 2 tbsp brandy, thyme sprigs, and bay leaf. Bring to a boil, then simmer for 20 minutes until the flavors are unified and bold.
  7. While the soup simmers, toast your baguette slices in the oven. Once golden, rub each slice with the peeled garlic clove until the aroma is fragrant.
  8. Remove the thyme and bay leaf. Ladle the soup into oven safe crocks, place a toasted baguette slice on top, and pile on the 2 cups of grated Gruyere and 1/4 cup Parmigiano Reggiano.
  9. Place the crocks on a baking sheet and broil for 3 minutes until the cheese is bubbly and brown spotted.