In a large skillet, brown ground beef, drain off all fat. Stir in next 9 ingredients: simmer 10 minutes, stirring occasionally.
In a small bowl, combine milk, oil and eggs; beat 1 minute at medium speed. Lightly spoon in flour and salt; beat 2 minutes at medium speed or until smooth. Pour hot meat mixture into an ungreased 9 x 13-inch baking pan. Top with mozzarella cheese, covering filling completely. Pour batter over all and sprinkle with Parmesan cheese. Bake for 25 to 30 minutes or until puffed and deep golden brown.
Serve immediately, cutting into squares to serve.