Cook the potatoes: Place the quartered potatoes in a large pot and cover with cold water. Add a pinch of salt. Bring to a boil over medium-high heat, then reduce to a simmer. Cook until the potatoes are tender but still firm, about 15–20 minutes. Test by piercing a potato with a fork—it should slide in easily without the potato falling apart. Drain and allow the potatoes to cool slightly.

Prepare the dressing: While the potatoes are cooking, whisk together olive oil, red wine vinegar, Dijon mustard, minced garlic, dried oregano, salt, and black pepper in a small bowl. Taste and adjust seasoning if needed. The dressing should be bright, tangy, and fragrant with garlic and oregano.

Assemble the salad: In a large mixing bowl, combine the warm potatoes with red onion, cherry tomatoes, kalamata olives, and capers if using. Pour the dressing over the potatoes while they are still slightly warm so they absorb more flavor. Toss gently to coat evenly without breaking the potatoes.

Add finishing touches: Sprinkle crumbled feta cheese over the salad and fold it in carefully. Garnish with freshly chopped parsley for a pop of color and fresh herbal aroma. Taste again and add more salt or pepper if desired.

Chill and serve: Greek Potato Salad can be served slightly warm, at room temperature, or chilled in the refrigerator for 30–60 minutes to let the flavors meld. Give it a gentle toss before serving and drizzle a little extra olive oil on top for shine.