Cook the cauliflower in simmering water until soft, about 15-20 minutes. Drain. (On the CheapCooking theme, save the water for some soup.)
Mash the cauliflower, milk, egg, cheese, and 2 Tbs of the butter together. Spread in a greased loaf pan or small casserole dish. Sprinkle the bread crumbs on the top and dot the last tablespoon of butter on it.