Everybody wants a make-ahead breakfast of their repertoire, and this one feeds a crowd. The celebs of this bread-pudding-like casserole are mushrooms, leeks, asparagus, and spinach, so everybody can begin their day loaded with veggies. Pour a easy egg custard flavored with chives and Dijon mustard over sauteed veggies, whole-grain bread, and Asiago cheese. Then let all of it soak in a single day (or for at the least an hour) earlier than ending it within the oven. There is no scarcity of taste on this satisfying breakfast casserole.