Bring a large pot of generously salted water to a boil. Add the potatoes and cook until fork tender, about 20–25 minutes depending on their size.
Drain the potatoes and allow them to cool just enough to handle. Peel while still warm, then cut into bite-sized cubes.
Transfer the potatoes to a large mixing bowl. Add the tomatoes, capers, olives, and thinly sliced red onion.
Drizzle in the red wine vinegar first, followed by the extra virgin olive oil. Season with the oregano, salt, and freshly ground black pepper, q.b., then gently toss until evenly coated.
Fold in the torn fresh basil and give the salad one final gentle toss.
Let the salad rest at room temperature for 15–20 minutes before serving. This allows the potatoes to absorb the dressing and the flavors to fully develop.