Cook first 3 ingredients in a large saucepan, coated with cooking spray, over medium-high heat, stirring until beef crumbles and is no longer pink. Drain and pat with paper towels. Wipe dripping from skillet with a paper towel.
Return beef mixture to skillet. Stir in tomato sauce and next 5 ingredients. Cover and cook over medium-low heat for 10 minutes. Pour into a lightly greased 2 quart baking dish.
Prepare cornbread batter according to package directions using skim milk. Pour over beef mixture.
Bake at 400 degrees F for 30 minutes or until lightly browned.