Sprinle evenly with 1-2 tsps of the cornmeal. Divide dough into thirds. Sprinkle evenly with rest of cornmeal. Press lightly into crusts. Place on coated cookie sheets.
Prick crusts generously with fork.
Bake at 450 F. for 8 minutes. Meanwhile, in medium skillet brown ground beef and onion. Add taco sauce and mix well. Spread evenly over partially baked crusts. Sprinkle with cheese.