Peel the potatoes and cut them into thin slices.

Peel and finely slice the onion.

Heat the olive oil in a large non-stick frying pan over medium heat.

Add the potatoes and onions to the pan, season with salt, and cook slowly, stirring occasionally until the potatoes are tender but not browned.

In a large bowl, beat the eggs, then season with salt and black pepper.

Drain the potatoes and onions and mix them in with the beaten eggs.

Remove excess oil from the pan, leaving a bit just to coat it, and return to a medium-low heat.

Pour the egg and potato mixture back into the pan. Cook slowly, shaking the pan occasionally to prevent sticking.

When the mixture is mostly set, use a plate to help flip the omelette and cook the other side until done.

Slide the omelette onto a plate, let it rest for a few minutes, then slice into wedges.

Garnish with fresh parsley and serve with bread and a green salad.