Peel the potatoes and the onions. Cut the potatoes in half and then slice them. Chop the onions.

Place the potatoes and onions in a saucepan. Add a generous amount of oil, enough to cover the potatoes. Fry until golden brown on medium heat (this could take up to 30 min, however just check by eye rather than sticking to a time!)

Remove from the heat once the potatoes are golden brown.

Strain the potatoes and onions. Season them with salt.

Whisk the eggs in a separate bowl and season with salt. Add the potato mixture into the bowl and mix. Heat a tablespoon of oil in a small or medium sized pan (the size of this pan will determine the shape of the tortilla). Add the mixture into the pan and cook on medium heat.

Let the tortilla cook on this side until it is stable enough to flip. This usually takes about 5 minutes. Place a plate upside down over the pan and flip the tortilla onto it in one swift motion. Do this quickly, as a portion of the egg might still be liquid and could spill.

Slide the tortilla back into the pan. Don’t worry if this gets a little messy. Let it cook on this side until it is done (it is a little bit tricky to figure out how long this takes. This side definitely cooks much faster than the first side. It might only take one or two minutes. Be careful not to overcook it!)

Place the tortilla on a new plate and serve. While it tastes yummy when served warm, the cold leftovers are just as delicious! (Snack tip: place a slice of tortilla between two halves of a buttered bread roll for a “bocadillo de tortilla”)