Quiche can be served hot, warm, room temperature and reheated from baked and chilled the day before a brunch. You can also cook the leeks, par-bake the shell and make the custard the night before, assemble and bake in the morning. Make sure to whisk the custard thoroughly before adding to the shell. If all the ingredients are fridge cold, baking may take a few extra minutes. To go crustless, butter a 9-inch pie pan on the bottom and sides. Sprinkle ¼ cup dried breadcrumbs across the bottom before adding the leeks and custard.