Turn the dough onto a lightly floured surface. Lightly flour your hands and shape the dough into a ball. Fold the top toward you. With your palms, push it away with a rolling motion. After each push, give the dough a quarter turn and fold it toward you again. As you knead, add flour to the surface only as needed to keep dough from sticking. Continue kneading in this manner until the dough is smooth and elastic, typically about 6 to 8 minutes.