1 lb. lean ground beef
1 c. Cheddar cheese, shredded
1/3 c. mayonnaise
1/3 c. sour cream
1 tbsp. onion, finely chopped
1 c. biscuit baking mix
1/4 c. cold water
1 small tomato, sliced

In a nonstick skillet, cook beef until no longer pink; drain. Remove from heat. Stir in cheese, mayonnaise, sour cream and onion. In a bowl, combine biscuit mix and water. Spread into an 8-inch square baking dish coated with nonstick cooking spray. Top with beef mixture and tomato.

Bake, uncovered, at 375°F for 20 minutes or until bottom crust is golden brown.