Metzger’s Baked French Onion Soup Recipe

Prepare onions

Peel and thinly slice enough yellow onions to yield about 6 cups (approx. 4–5 medium onions).

In a large heavy-bottomed pot or Dutch oven, melt 4 tbs unsalted butter with 1 tbs olive oil over medium heat until shimmering.

Add the sliced onions, 1 tsp kosher salt, 1 tsp freshly ground black pepper, and 1 tsp granulated sugar. Stir to coat. Cook onions, stirring frequently, for 25–35 minutes, reducing heat to medium-low as needed. The onions should become deeply golden-brown and caramelized but not burnt (adjust heat if they start to char).

Once caramelized, sprinkle 2 tbs all-purpose flour over the onions and cook, stirring, for 1–2 minutes to remove the raw flour taste and to help thicken the soup slightly.

Deglaze the pot with 1 cup dry white wine (if using). Scrape up browned bits from the bottom with a wooden spoon and simmer until the wine is almost fully reduced, about 2–3 minutes.

Add 6 cups beef stock and 2 cups beef bone broth (or additional stock), 3 thyme sprigs, 2 bay leaves, and 1 tsp Worcestershire sauce. Bring to a gentle simmer, then reduce heat and simmer uncovered for 20–30 minutes to blend flavors. Taste and adjust seasoning with salt and pepper as needed. Remove and discard thyme stems and bay leaves before serving.

Preheat the oven to 400°F (200°C) or set a broiler to high if you will broil the assembled bowls.

Brush both sides of 4 large 1-inch-thick bread slices with 2 tbs melted butter. Place the slices on a baking sheet and toast in the oven until golden and crisp, about 8–10 minutes, flipping once. Alternatively, broil for 1–2 minutes per side — watch closely to avoid burning.

When the toasted bread is still warm, rub the top surfaces lightly with the cut side of 1 garlic clove to impart a mild garlic flavor.

Divide the hot soup among 4 ovenproof bowls (ramekins or crocks). Place one large toasted crouton on top of each bowl so it floats on the surface.

Arrange about 2 oz Swiss cheese over each crouton (total 8 oz for 4 bowls), covering the bread and slightly overlapping the rim of the bowl so cheese will melt down into the soup. Sprinkle each with about 1/2 tbs grated Parmesan, if using.

Place the bowls on a baking sheet and transfer to the preheated oven. Bake at 400°F (200°C) until the cheese is fully melted, bubbling, and lightly browned on top, about 8–12 minutes. If using the broiler, broil 2–4 minutes watching constantly to avoid burning.

Carefully remove the hot bowls from the oven with oven mitts. Let cool 1–2 minutes to settle, garnish with 1 tbs chopped parsley divided among the bowls, and add extra black pepper to taste.

Serve immediately with a spoon. Caution diners that bowls and cheese will be very hot.