Heat oil over a medium low heat in a 6" cast iron skillet or nonstick skillet.

Add potatoes and onions and stir to coat with oil. Let them cook over low heat until cooked through. The potatoes should not brown during this process and are done when they break apart easily when pressed with a spoon.

Beat the eggs in a bowl large enough to hold the potato and onion mixture with a teaspoon of salt.

When the potatoes are done, add them to the beaten eggs and mix together gently breaking some of the potatoes.

Remove the excess oil from the pan leaving only a tablespoon. Add the potato and egg mixture to the pan and let cook over low heat for about 5 minutes or until set on the bottom but uncooked on the top.

Using a skillet lid larger than the skillet (a large plate will suffice but will be more unwieldy) invert the tortilla onto the lid and slide back into the skillet to cook the other side.

If using an electric stove you can turn it off and set the skillet back on the eye for about 5 minutes. If using a gas stove, turn it to lowest setting and let cook for 5 minutes. Be careful not to burn the bottom.

When done, turn out onto a serving dish and cut into triangles if using for a side or little squares if using as an appetizer.

¡Que aproveche!