Combine the masa harina, salt and water. Stir until you get a moist, but not sticky, dough. Put them in the refrigerator for 30 minutes.
Shape the dough into balls to the size of a golf ball. Roll out the balls on a lightly floured surface. Keep the shape round and roll until paper thin and a diameter of about 12 cm. Stack them up interleaved with non sticking paper.
Heat a flat pan without oil and cook the tortillas in about 2-3 minutes on each side until they are golden brown.