Combine the ground beef, milk, egg, garlic and seasoning in a bowl; blend well. Press the beef mixture evenly on the bottom and up sides of an ungreased 9-inch pie plate. Layer with the ketchup, chopped onion, olives, and cheese. Bake in a preheated 400° oven for 30 to 35 minutes. Sprinkle with the parsley and cut into wedges. Serve cheeseburger pie hot.