Reduce the heat to low, add the egg mixture and stir it occasionally with a wooden spatula until the eggs begin to solidify. After about 5 minutes, when the egg mixture is not liquid on top any more, cover the pan. Check occasionally and if bubbles form, prick them with a fork. Cook to build a brown crust on the tortilla bottom, about 15 minutes more, occasionally sliding a spatula around the bottom to prevent sticking.
Comments: The tortilla may be eaten cold, but I prefer it hot with good fresh bread.