How to Make It
In a medium bowl, mix the masa with the water until a dough forms. Cover and let stand for 1 hour.
Divide the dough into 12 equal pieces (or 6 pieces for 8-inch tortillas) and roll each piece into a ball. Line a tortilla press with parchment paper or plastic wrap and press the 12 balls of dough into 5-inch tortillas. If making 8-inch tortillas, roll them out with a rolling pin.
Heat a griddle or cast-iron skillet. Working in batches, cook the tortillas over moderate heat, turning, until cooked through, about 6 minutes.