Using a mandoline or knife, slice the potatoes and onions about 1/8th of an inch thick.

Add them to a pot and add your olive oil.

Over medium heat, bring the olive oil to a simmer, and allow the potatoes and onions to slowly cook for about 25 minutes. They will become soft and soak up the flavor of the olive oil .

While your potatoes and onions are simmering, scramble 8 large eggs and set aside.

Once your onions and potatoes are done, use a strainer to drain out the oil. Save the oil to cook your tortilla.

Once strained, add the onions and potatoes to the scrambled eggs and add salt. Stir to combine.

In a large frying/sautee pan, heat 1 tablespoon of the olive oil you drained over medium-low heat. Once hot, add your egg, potato, and onion mixture, evenly spreading out throughout the pan. Cook for 8-10 minutes until you are able to run a spatula along the border of the pan and can slightly lift the edge of the tortilla up. Flip the tortilla by placing a large plate on top of the pan, and turn upside down. Slide the tortilla back into the pan and cook for another 8-10 minutes. Both sides should be slightly browned.

Serve and enjoy!