Make pie shell. Combine 1 1/2 cups grated Swiss cheese and 4 teaspoons flour. Sprinkle in shell. Sprinkle on 1/2 cup diced ham. Combine 3 eggs, 1 cup milk, 1/4 teaspoon salt, 1/4 teaspoon dry mustard. Beat until smooth and pour over cheese and ham. Freeze. Bake at 400 degrees for about 1 hour. Cool slightly.