French Onion Lasagna

French onion lasagna layers noodles with caramelized onion gravy, Gruyere béchamel, buttery sourdough croutons, and golden mozzarella.

INGREDIENTS:

1 lb lasagna noodles, cooked

8 oz mozzarella cheese, grated

6 cups sourdough bread, cubed

1/4 cup olive oil

1 teaspoon granulated garlic

Kosher salt and freshly cracked black pepper, to taste

1/4 cup butter

1/4 cup flour

4 cups whole milk

2 cups gruyere cheese, grated

3 yellow onions, sliced

3 tablespoons unsalted butter

2 teaspoons fresh thyme

1 teaspoon Worcestershire sauce

1 tablespoon balsamic vinegar

1 quart good beef stock

Kosher salt and freshly cracked black pepper, to taste

DIRECTIONS:

Preheat oven to 375°F and grease a 10×14 lasagna pan or a 9×13-inch baking dish.

Toss cubed sourdough bread with olive oil and granulated garlic. Spread on a sheet tray, season with salt and pepper, and bake for 16–20 minutes until golden. Set aside.

Cook lasagna noodles in boiling salted water until al dente. Drain and set in cold water.

Caramelize sliced onions in 3 tablespoons butter over medium-low heat until golden brown.

Stir in flour, then add beef stock, thyme, Worcestershire, and balsamic vinegar. Simmer until thickened. Season to taste. Set aside.

For the béchamel: Melt butter in a saucepan, whisk in flour and toast 30 seconds. Add milk gradually, whisking constantly until thick. Stir in gruyere until melted. Season and blend if needed.

To assemble: Spread a little onion filling on the bottom of the pan. Layer noodles, 1/3 of onion filling, 1/3 croutons, drizzle béchamel. Repeat 2 more times.

Top with mozzarella and remaining gruyere cheese.

Bake uncovered for 35–40 minutes, or until cheese is golden. Let rest 10 minutes before slicing.