01 -
Grab a medium-sized (12-inch) nonstick pan and warm up the olive oil. Toss in the potatoes, cooking them until golden and crispy on the edges. Add the onion and let it soften up until it’s clear. Remove all the oil completely.
02 -
Put the potatoes and onions back in the pan, spreading them out so they make one even layer. Turn the heat way down.
03 -
Whisk the eggs with some salt and crushed black pepper. Pour the whisked eggs over the layer of potatoes and onions. Stir gently with a plastic spatula to make sure the eggs start cooking evenly.
04 -
Once the bottom is firm but the top is still a bit jiggly, cover the pan with a big plate. Hold the plate tightly and flip the tortilla over onto it. Slide it back into the pan for the other side to cook.
05 -
Cook the tortilla on low, giving the pan a shake now and then, until it’s totally done and sets all the way through.
06 -
Cover the tortilla with a clean plate, flip it out of the pan, and top it with parsley if you’d like. Slice it into squares and serve it warm or cool.