Tuna noodle, broccoli cheese, shepherd's pie? Sure, these stalwarts have a rich history and can be fashioned with panache. But, let's admit it, they're a little boring. To all who turn up their nose at casserole, please kiss my . . . casserole Why not look around the world and find inspiration? Ever try a Chinese shaguo? How about an Ethiopian wat? I'll bet you never even thought of cooking up an Icelandic Ofnsteiktur fiskur me lauk...