In small bowl, stir Bisquick® mix, cornmeal and very hot water until soft dough forms. Place on surface sprinkled with Bisquick mix, gently rolling to coat. Shape into ball; knead about 5 times or until smooth. Roll dough into 10-inch circle; fold into fourths. Unfold on pizza pan. In small bowl, stir together beans and salsa; spread over dough to within 2 inches of edge. Sprinkle with onions. Fold edge over. Sprinkle cheese over beans.