Boil the unpeeled potatoes in salted water, then leave to cool. Finally peel and dice. Put the potato cubes in a salad bowl. Peel the onions and cut into rings, clean and chop the parsley and add to the potatoes like the onion rings.
Pour the oil over it and season with salt and pepper. Mix well.
Note: The amount of oil seems like a lot, but the secret of the recipe is that the potatoes look well saturated with it.