Mushroom and Spinach Skillet Strata

A strata is essentially a savory bread pudding. Here, smoked Gouda lends a hearty richness to the classic pairing of spinach and mushrooms. Serve with a lightly dressed salad to round out the meal.

• 4 oz. baguette (about a 9-inch piece), cut into 1/2-inch cubes
• 1 Tbs. unsalted butter
• 1 medium yellow onion, halved and thinly sliced
• 4 oz. cremini mushrooms, trimmed and coarsely chopped (1-1/2 cups)
• 1 large clove garlic, minced
• 1 tsp. coarsely chopped fresh thyme
• Kosher salt and freshly ground black pepper
• 4 oz. baby spinach (4 lightly packed cups)
• 4 large eggs
• 1 cup whole milk
• 3 oz. smoked Gouda, coarsely grated (about 3/4 cup)

Position a rack in the center of the oven and heat the oven to 450°F.

Spread the bread cubes on a large rimmed baking sheet and toast in the heating oven until dry and pale golden, 3 to 5 minutes.

Meanwhile, melt the butter in a 10-inch ovenproof skillet with a lid over medium-high heat. Add the onion and cook, stirring occasionally, until tender but not browned, 3 minutes. Add the mushrooms, garlic, thyme, and 1/2 tsp. each salt and pepper. Cook, stirring occasionally, until the mushrooms are soft, about 3 minutes. Add the spinach and cook, stirring occasionally, until wilted, 1 to 2 minutes.

In a medium bowl, whisk the eggs, milk, 1/2 tsp. salt, and 1/4 tsp. pepper. Add the cheese and bread, toss until combined, and transfer to the skillet. Stir until all of the ingredients are distributed evenly and then press down on the mixture to flatten it a bit.

Bake, covered, for 10 minutes. Uncover and continue to bake until set in the center, about 5 minutes more. Let cool briefly, slice, and serve.