Brown ground beef and drain. Add onion, cook together for approx. 3 mins. Add ketchup and cook together until heated through. Place 1 pkg of crescent rolls to the bottom of a 9 inch pie tin. Spread the dough around until bottom and sides of tin are covered. Add your hamburg mixture to pie tin and place cheese on top. Use the second pkg of crescent rolls for the top crust. It can be a bit tricky but doesn't need to look pretty. Brush melted butter on top crust and place in oven at 400 until crust is brown. Approx. 20 mins.