Use a large bowl to combine the masa-harina (corn flour) and water. Mix well until the water is absorbed evenly and the dough forms a ball.
Preheat a griddle or heavy skillet on medium flame. This has to be ready when you start pressing the tortillas.
After kneading the dough, form a small ball the size of a golf ball. Using a tortilla press or a heavy dish, (pie dish as I do), place the ball of the dough about 1 ½ inch in diameter between the two plastic pieces and press to form a 6 inch round tortilla.
Open the tortilla press or remove the heavy dish if using to press the tortillas, peel the top plastic off. Lift the tortilla from the tortilla press holding it from the bottom part. If the dough is too dry, the edges of your tortilla will look cracked and you will need to add a little water.
Somehow when using the tortilla press my tortillas come out very thin. Some people in the South of Mexico eat thicker tortillas and some grandmas still make them by hand.
Lift the plastic with the pressed tortilla, place the dough in your hand closer to your fingers and carefully peel the plastic off the dough. If the dough doesn’t come out so easily then the dough could be a little too wet. Add some more masa-harina to the dough mix again until it becomes easy to handle.
Place the tortilla on the griddle and cook for about 30 -40 seconds. The edge will begin to dry out. Turn over and continue to cook for about 40-45 seconds until brown patches form. This time will vary depending on how thick is your tortilla and the temperature of your griddle.
Turn over again and cook for another 15 seconds. The cooking time is about 1:45 minute’s total. Cook until the tortilla begins to puff. Tap lightly with your fingertips to allow even puffing. Wrap with a napkin or clean towel, and serve. Tortillas keep warm when placed in a basket made of natural fibers.