Peel & dice your potatoes.
Heat a frying pan with a generous amount of extra virgin olive oil, and add the diced potatoes.
Fry your potatoes until they’re cooked & crispy.
In the meantime, cut your chorizo into quarters and chop your onion.
Add the chorizo & onion to the frying pan and fry until the onion is nice and soft.
Beat the eggs, and add salt & pepper to taste (be mindful of the salt due to the amount of added chorizo, however).
Add the egg mixture to the pan while gently mixing the potatoes and other ingredients around so that everything gets evenly coated & distributed.
Gently shake the pan every now and then, so that the eggs on top cook more evenly.
When the bottom of the omelet seems cooked and crispy, and the top is mostly solid, place the flat dinner plate on top of the pan. Hold one hand on top of the plate, and flip the tortilla onto the plate. Place your pan back onto the stove and carefully slide the Spanish omelet from the plate, back into the pan.
Cook the omelet until it’s fully cooked through.
Carefully slide the omelet from the pan, onto a plate. Garnish the Spanish omelet with fresh parsley, then serve. Buen provecho!