A great way to use up leftover challah, this challah strata with mushrooms, peppers, and asparagus makes a delicious brunch dish or late-night dinner. If you're serving a crowd, you can double the recipe and bake it in a 13" X 9" Baking dish. Make it a meal: this savory strata is perfect for when you're craving breakfast for dinner. Serve with a simple salad of romaine lettuce with sun-dried tomatoes and pecans, and a glass of wine.