Ingredients
Equipment
Instructions
- In a large Dutch oven, melt butter and olive oil over medium heat. Add slivered onions and 1 tsp salt. Cook, stirring occasionally, for 45-60 minutes until the onions are soft, jammy, and a deep amber-brown color.
- Sprinkle the flour over the caramelized onions and cook for 1 minute, stirring constantly. Pour in the sherry to deglaze, scraping all browned bits from the bottom of the pot. Cook until the sherry has nearly evaporated.
- Stir in the beef broth, thyme sprigs, and bay leaves. Bring to a boil, then reduce heat to low, cover, and simmer for at least 30 minutes. Remove thyme and bay leaves before serving.
- Preheat your broiler. Place baguette slices on a baking sheet and broil for 1-2 minutes per side until dry and lightly toasted.
- Ladle hot soup into oven-safe bowls. Top each with a toasted baguette slice and a generous pile of grated Gruyere cheese, covering the edges of the bowl. Place on a baking sheet and broil for 2-4 minutes until the cheese is bubbling, golden-brown, and has charred, crispy edges. Garnish with fresh thyme leaves and serve.
Notes
Uniform Slices: Try to slice your onions to a uniform thickness to ensure they all cook at the same rate.
Don't Rush Caramelization: Low and slow is the only way to develop the deep, sweet flavor without scorching the onions.
Use Room Temperature Cheese: Let your grated cheese sit out for 15-20 minutes before using for a more even melt.
Know Your Broiler: Stay right by the oven and watch the cheese constantly to prevent it from burning.
Don't Rush Caramelization: Low and slow is the only way to develop the deep, sweet flavor without scorching the onions.
Use Room Temperature Cheese: Let your grated cheese sit out for 15-20 minutes before using for a more even melt.
Know Your Broiler: Stay right by the oven and watch the cheese constantly to prevent it from burning.
