Start by cutting the onion into strips and set aside.
In a skillet, place the olive oil or oil, spread it well all over the skillet. Add the onion strips and mix until golden.
Cut the peeled potatoes in half then into round slices, transfer them to the skillet, mix well and let it cook for 10 to 15 minutes. If you want, add some water.
Into a bowl, add the eggs, the salt and the black pepper, whisk very well until combined.
After the potatoes have cooked through, turn off the heat and transfer them to the bowl with eggs, mix well. Cover the bowl and let it rest for 10 to 15 minutes.
After this indicated time, pour a drizzle of olive oil or oil into a skillet, transfer allthe potato mixture to it and let it cook for 3 to 5 minutes.
Flip and cook the other side for 2 to 3 minutes.
When golden, turn off the heat.
Serve.