I cleaned the potatoes, washed them well, then cut them into squares and put them in boiling salted water.
I also put the eggs in boiling salted water.
In the meantime, I cleaned the onion, washed it and cut it. The olives were pitted so I had to clean them to remove the seeds.
When the eggs and potatoes were cooked I put them aside. I put the potatoes in a strainer to drain all the water, and I put the eggs in cold water to cool (and here's another secret if you put cold water immediately over the eggs it cleans better) after which I cleaned. When they were ready, I cut them into pieces over olives and onions, then I put the potatoes and salt, pepper, vinegar, oil and mixed. That's about it, good appetite!