1Heat oven to 400°F. In small bowl, stir together Bisquick® mix, 1 cup of the cheese, the water and egg; set aside.
2In ovenproof 10-inch skillet, cook beef over medium heat about 8 minutes, stirring occasionally, until brown; drain. Stir in ketchup, salt and tomato sauce. Heat over medium-high heat, stirring occasionally, until hot.
3Pour Bisquick mixture over top. Bake 25 to 30 minutes or until golden brown. Sprinkle with remaining 1/2 cup cheese.