Brown hamburger until done, spoon from pan into doubled pie crust. In same pan fry onion till tranparent, spoon onto hamburger. Mix katchup unto the Pork and beans, pour it over the top of hamburger and onions, sprinkle some cheese on top. Bake about 35 to 45 minutes in a 400 oven until hot though and cheese is browned. Serves 4 by itself, but with a side of corn or peas, and salad it will feed 6.