We clean the potatoes, peel and chop them into thin layers. Laminate the onion (if you want onion. You can do it without it).
Fry everything in a pan with olive oil. This is best done on low heat.
Beat eggs and add salt.
When browned, remove the potatoes from heat and drain on paper towels. Pour the potato in the beaten egg and make sure that the eggs cover the potatoes.