FALL

Spinach and Gruyère Strata

This rich and cheesy make-ahead casserole is perfect for cool-weather entertaining.

Serves 8

2 tablespoons unsalted butter, plus additional for greasing pan

1 medium onion, chopped

½ pound cremini or button mushrooms, sliced

Salt and black pepper

8 cups cubed (¾ inch) challah or brioche bread

2 cups (about 6 ounces) Gruyère or Jarlsberg cheese, shredded

1 cup Parmesan cheese, grated

1 package (10 ounces) frozen spinach, thawed and drained of excess liquid

2½ cups whole milk

9 large eggs

½ teaspoon dry mustard powder

1. Butter a 9-by-13-inch glass baking pan. Melt butter in a large cast-iron or heavy skillet over medium heat. Add onions and mushrooms; season with salt and pepper. Cook 8 minutes, until mushrooms release their liquid, stirring often.

2. Spread about one-third of the bread cubes in the prepared baking pan. Top with half of each cheese, half of the mushroom mixture and half of the spinach leaves. Top with one-third of the bread and the remaining mushrooms, spinach and cheese. Top everything with the remaining one-third of the bread.

3. In a large bowl, whisk milk, eggs, mustard powder, salt and pepper until blended. Pour evenly over casserole. Cover with plastic wrap and chill strata for at least 8 or up to 24 hours.

4. Remove strata from the refrigerator at least 30 minutes before baking. Preheat oven to 350°F. Bake, uncovered, 40 to 45 minutes, until golden and cooked through. Let stand 10 minutes before serving.

TIP: Don’t worry about making the layers perfect—everything bakes together into one pan of creamy deliciousness.