Beef mixture can be microwaved. For step 2, crumble ground beef into microwavable 2-quart casserole. Cover and microwave on High 6 minutes, stirring every 3 minutes, until no longer pink; drain. Stir in ketchup, salt and tomato sauce. Cover and microwave on High 4 minutes or until hot and bubbly; stir. Pour Bisquick mixture over top. Continue with step 3, baking in the casserole 27 to 32 minutes.
Any flavor of reduced-fat cheese can be used instead of the Cheddar.