01 -
Warm up the olive oil in a medium nonstick pan, around 12 inches wide. Fry the potato chunks until they're golden, crispy, and soft inside. Toss in the onion and sauté until see-through. Once done, drain all the oil.
02 -
Put the cooked onions and potatoes back in the pan, spreading them evenly into one layer. Turn the heat down to low.
03 -
Whisk the eggs with the salt and pepper. Pour this mixture into the pan. Gently stir everything with a plastic spatula so the eggs cook evenly underneath.
04 -
Once the bottom has set but the top is still a little wet, cover the pan with a large plate. Hold the plate tightly, flip the tortilla onto it, and carefully return it to the pan to cook the other side.
05 -
Let it continue cooking, giving the pan a light shake now and then, until the tortilla is cooked all the way through.
06 -
Place a clean plate back on the tortilla, flip the pan over, and let it slide out. Sprinkle with parsley if you like. You can serve it warm or let it cool and enjoy in slices.