Wash and boil the potatoes without peeling them by placing them in cold salted water for about 30-35 minutes (the exact cooking time will vary depending on their size), then drain and peel them while they are still hot and leave them to cool.
When they are cool cut them into slices of thickness of about 1 cm. Then peel the onion and cut it into slices (or rings), then put it for about 30 minutes to soak in vinegar, then drain it good.
Wash the tomatoes, cut them in half and crush them slightly to pop out all the seeds and vegetation waterand put them to drain in a colander with the cut side down.
Put the capers in a colander and rinse thoroughly under running water for. Gently crush the olives and remove the core.
Gather in a large bowl the tomatoes, the onion, the drained capers, the pitted olives, the sliced potatoes and season with extra virgin olive oil combined with plenty of oregano, basil, salt, pepper and a few drops of vinegar. Mix together gently and serve.