In a greased 3-qt. or 13x9-in. baking dish, arrange French bread or croissant halves with sides overlapping. , In a large bowl, combine the eggs, milk, spinach, salt, nutmeg and pepper; pour over bread. Sprinkle with cheeses. Cover and refrigerate for 8 hours or overnight. , Remove from the refrigerator 30 minutes before baking. Bake, uncovered, at 350° until a knife inserted in the center comes out clean, 40-45 minutes. Let stand for 5 minutes before cutting. Serve warm.