Baked French Onion Soup Recipe

Prepare onions

Peel and thinly slice onions to yield about 6 cups. Combine butter and olive oil in a large heavy-bottomed Dutch oven or saucepan over medium heat until butter melts.

Add sliced onions, sprinkle with 1 tsp salt and 1 tsp sugar. Cook, stirring frequently, for 20–30 minutes until onions are deeply caramelized and golden brown. If onions begin to stick, lower heat and stir more often; add a tablespoon or two of water if they brown too quickly.

Stir in 1 tablespoon flour and cook for 1–2 minutes to remove raw flour taste and help thicken the soup slightly.

Pour in 1 cup dry white wine to deglaze the pan, scraping up browned fond from the bottom. Simmer until most of the wine has evaporated, about 2–3 minutes.

Add 6 cups beef stock, 2 bay leaves, 3 thyme sprigs and 1 tsp Worcestershire sauce. Bring to a simmer, reduce heat to low and cook gently, uncovered, for 20–25 minutes to allow flavors to meld. Taste and adjust salt and pepper as needed (use additional up to the finishing amounts). Remove and discard thyme sprigs and bay leaves before serving.

Preheat oven broiler or set oven to 425°F (220°C) if broiler isn't available.

In a small bowl, combine 4 tablespoons softened butter, 3 minced garlic cloves, 1 tablespoon chopped parsley, 1 teaspoon olive oil (optional) and 1/4 teaspoon salt until smooth.

Spread garlic butter evenly on one side of each baguette slice. Place slices buttered-side up on a baking sheet and broil or bake 2–4 minutes, watching closely, until edges are golden and fragrant. Remove and set aside.

Preheat oven to 400°F (200°C) if not already at broil temperature. Ladle hot soup into oven-safe bowls (ramekins or crocks), filling each about 3/4 full. Remove any excess fat from surface if present.

Place one garlic toast slice on top of each bowl (buttered side up) or beside it if you prefer to serve the toast on the side.

Top each bowl with a layer of provolone (about 1–1.5 oz per bowl) then sprinkle generously with grated asiago (about 2 tablespoons per bowl). For a more melty top, place a second small piece of provolone over the asiago.

Place bowls on a baking sheet and bake at 400°F (200°C) for 8–12 minutes until cheese is melted and bubbling. For a browned crust, switch to broil for 1–2 minutes—watch closely to avoid burning.

Carefully remove hot bowls from oven. Season with a light pinch of coarse sea salt and a grind of black pepper to taste. Let cool 3–5 minutes before serving. Serve hot with extra garlic toasts on the side.