Press each biscuit into 5 1/2-inch round. Coat both sides of each with cornmeal; place on ungreased cookie sheet.
Bake at 375°F 11 to 13 minutes or until bottoms are golden brown. Meanwhile, place beans in medium microwavable bowl. Cover; microwave on High 1 to 2 minutes or until hot.
Spread about 1/4 cup beans and 1/4 cup cheese on each round. Bake about 2 minutes longer or until cheese is melted. Top each with lettuce; fold in half.