Spanish Potato Omelette (Tortilla)

Heat 1 1/2 cups oil in a nonstick skillet. Add potato slices and onion, and cook covered, over low heat, for 20–30 minutes. It’s done when potatoes are tender. Remove potato slices and onion from skillet and drain in a colander. Put on paper towels. Wipe out the skillet using paper towels.

Beat eggs in a bowl. Add potatoes and onions and mix. Season with salt and pepper.

Heat 1 tablespoon olive oil in the same pan. Add the egg mixture and cook, over low heat, for 3–4 minutes. Place a plate or a lid (it should be bigger than your skillet) on the top of the pan and flip it. The omelette should be on a lid now.

Heat remaining 1 tablespoon olive oil and put the omelette back in. Cook for 2–3 minutes more. Serve either warm or cold.