In a bowl, combine milk, bread crumbs, and garlic salt. Add beef; mix well. Press meat mixture onto the bottom and 1" up the sides of a greased 9" pie plate. Bake, uncovered, at 350 for 20 minutes; drain. Spread top with ketchup. Sprinkle with cheddar cheese, oregano, and Parmesan cheese. Bake 3-5 minutes longer or until meat is no longer pink and cheese is melted.