Heat oven to 450 degrees. Cook ground beef and onion until beef is brown; drain. Spoon into ungreased 13x9x2" baking dish. Stir in soup, 1 cup of the milk, the garlic salt and vegetables.

Stir baking mix and remaining milk until blended. Pour over beef mixture.

Bake 27 to 30 minutes or until crust is light golden brown. Sprinkle with parsley if desired.