It's the morning after a weekend of heavy eating, and still you have family and friends visiting, sleeping in, slouching over their first cups of coffee, needing to be fed. By this time, everyone has had their fill of turkey-potato-stuffing leftovers. You want to send them home with a great breakfast, one that's easy on the cook and a bit kinder to the waistline, and you can't go wrong with an egg and cheese casserole packed with vegetables. After just a few minutes' work, and 35 minutes in the oven, something pouffy and tantalizing emerges, and your guests will feel loved and pampered and never know how simple it was for you to create. In this version, combine low-fat shredded mozzarella cheese with a little bit of goat cheese for a creamy texture. Leeks contribute a sweeter flavor than onions, though either would be fine here. Just add toast, orange juice, the Sunday newspapers, and, well... more coffee.