Instructions
Step 1: Prepare the Onions
Heat the Oil and Butter: In a large pot over medium heat, combine olive oil and butter. Allow the butter to melt.
Add the Onions: Stir in the thinly sliced onions, sugar, salt, and pepper. Cook for about 30 minutes, stirring frequently until the onions become caramelized and golden brown.
Step 2: Build the Flavor
Add Garlic and Herbs: Once the onions are caramelized, add minced garlic and thyme. Sauté for an additional 2 minutes until fragrant.
Deglaze the Pot: Pour in the white wine (if using) and scrape any brown bits from the bottom of the pot. Let it simmer for about 5 minutes until the wine reduces slightly.
Step 3: Simmer the Soup
Add Broth and Bay Leaf: Pour in the beef or vegetable broth and add the bay leaf. Bring the soup to a boil, then reduce the heat and let it simmer for 10-15 minutes.
Taste and Adjust: Remove the bay leaf, taste the soup, and adjust the seasoning with salt and pepper as needed.
Step 4: Prepare the Topping
Toast the Bread: While the soup is simmering, preheat the broiler. Toast the slices of bread until golden brown, then set aside.
Step 5: Assemble and Broil
Ladle the Soup: Divide the soup into oven-safe bowls, placing a slice of toasted bread on top of each bowl.
Add Cheese: Generously sprinkle the grated cheese over the bread.
Broil: Place the bowls under the broiler for 2-3 minutes, or until the cheese is melted and bubbly. Keep an eye on it to prevent burning!
Variations
Vegetarian Option: Use vegetable broth instead of beef broth and skip the cheese or use a dairy-free alternative.
Cheesy Delight: Experiment with different cheeses such as Fontina or Gouda for varied flavor profiles.
Herbal Twist: Add a splash of balsamic vinegar or fresh herbs like rosemary for a different depth of flavor.