Spinach & Feta Strata

Coat a 9-by-13-inch baking dish with cooking spray.

Heat oil in a large skillet over medium-high heat. Add scallions and leek; cook, stirring occasionally, until soft and browned on the edges, 8 to 10 minutes. Add spinach, 1/4 teaspoon ground pepper, 1/8 teaspoon salt and crushed red pepper; cook until the water has evaporated, about 2 minutes more.

Lay one-third of the bread in a single layer in the prepared pan. Dot with one-third of the spinach mixture. Sprinkle with 1/2 cup feta and 1/4 cup Parmesan. Repeat the layers twice more with the remaining bread, spinach mixture and cheeses.

Whisk eggs, milk, mustard and the remaining 1/4 teaspoon pepper and 1/8 teaspoon salt in a large bowl until smooth. Pour the mixture evenly over the strata. Gently press down on the top layer of bread to make sure it's submerged. Cover with plastic wrap and refrigerate for at least 8 hours or up to 2 days.

When you're ready to bake, let the strata stand at room temperature for 45 minutes. Preheat oven to 350°F.

Bake the strata until puffed and golden brown and a knife inserted in the middle comes out clean, 50 to 60 minutes. Let stand for at least 5 minutes before serving.