spinach and gruyère breakfast strata

 

INGREDIENTS :

• 8-10 1/2-inch slices supermarket French bread
• 5 tablespoons unsalted butter, softened, divided
• 4 medium shallots, minced (about 1/2 cup)
• 1 (10-ounce) package frozen chopped spinach, thawed and squeezed dry
• salt and freshly ground black pepper
• 1/2 cup medium-dry white wine, such as Sauvignon Blanc
• 6 ounces Gruyère cheese, grated (about 1 1/2 cups), divided
• 6 large eggs
• 1 3/4 cups half-and-half

INSTRUCTIONS :

1. Heat oven to 225°F and place oven rack in middle position. Arrange bread in single layer on large baking sheet and bake until dry and crisp, about 40 minutes, turning slices over halfway through. When cooled, butter slices on one side with 2 tablespoons butter; set aside. Alternatively, you can use stale bread or set the slices out to dry overnight. 
2. In a medium skillet set over medium heat, melt 2 tablespoons butter. Sauté shallots until fragrant and translucent, about 3 minutes. Add spinach, a pinch of salt, and a few grinds black pepper and cook, stirring occasionally, until spinach and shallots are fully combined, about 2 minutes. Transfer mixture to medium bowl; set aside. Add wine to skillet, increase heat to medium-high, and simmer until reduced to 1/4 cup, 2 to 3 minutes. Remove from heat. 
3. Butter 8-inch square baking dish with remaining 1 tablespoon butter. Arrange half the bread slices, buttered-side up, in single layer in dish. Sprinkle half of spinach mixture then 1/2 cup grated Gruyère evenly over bread slices. Arrange remaining bread slices in single layer over cheese; sprinkle remaining spinach mixture and another 1/2 cup cheese evenly over bread. Whisk eggs in medium bowl until combined; add reduced wine, half-and-half, 1 teaspoon salt, and a few grinds pepper and whisk to combine. Pour egg mixture evenly over bread layers; cover surface with plastic wrap, weigh down (using boxes of powdered or brown sugar, a bag of rice, etc.), and refrigerate at least 1 hour or up to overnight. Weighing the strata down helps improve its texture. 
4. A little over an hour before serving, remove the dish from refrigerator and let stand at room temperature 20 minutes. Meanwhile, adjust oven rack to middle position and heat oven to 325°F. Remove plastic wrap, sprinkle remaining 1/2 cup cheese evenly over surface, and bake until the  edges and center are puffed and edges have pulled away slightly from sides of dish, 50 to 55 minutes. Cool on wire rack 5 minutes before serving.