Beginning with corn flour, or masa, add water until a dough forms, then cut into portions, flatten and fry in hot oil. Basting the tortilla with oil causes air to get trapped and causes the tortilla to . . . puff! Flip over to cook the other side, then allow to drain over paper towels and serve open-faced and fill with your favorite toppings. Eat hot. So, so good! Get the recipe for Puffy Taco Shells.