Put this week’s bread loaf to good use with this spinach-kissed breakfast strata.
10 ounces spinach, washed
1½ cups finely chopped onion
3 tablespoons unsalted butter
¼ teaspoon freshly grated nutmeg
8 cups cubed Pain au Levain bread
2 cups grated Gruyère cheese
1 cup finely grated Grana-style cheese
2¾ cups milk
9 large eggs
2 tablespoons Dijon mustard
1. In a large skillet, heat oil over medium-high. Add the spinach and cook, stirring constantly, until wilted, about 2 minutes. Transfer to a colander and drain, pressing with a rubber spatula to release as much liquid as possible.
2. Cook onion in butter in a large heavy skillet over moderate heat, stirring, until soft, 4 to 5 minutes. Add ½ teaspoon salt, ¼ teaspoon pepper, and nutmeg and cook, stirring, 1 minute. Stir in spinach, then remove from heat.
3. Spread one third of bread cubes in a buttered 3-quart gratin dish or other shallow ceramic baking dish and top evenly with one third of spinach mixture. Sprinkle with one third of each cheese. Repeat layering twice (ending with cheeses).
4. Whisk together milk, eggs, mustard, and remaining 1/2 teaspoon salt and 1/4 teaspoon pepper in a large bowl and pour evenly over strata. Chill strata, covered with plastic wrap, at least 8 hours (for bread to absorb custard).
5. Preheat oven to 350°F. Let strata stand at room temperature 30 minutes. Bake strata, uncovered, in middle of oven until puffed, golden brown, and cooked through, 45 to 55 minutes. Let stand 5 minutes before serving.