Wash the Yukon Gold or red-skinned potatoes under cold water, scrubbing away any dirt. Cut the potatoes into quarters for even cooking. Place them in a large pot and cover with water. Add a generous pinch of salt and bring to a rolling boil over high heat.

Reduce heat to a gentle simmer and cook the potatoes for about 15-20 minutes until fork-tender but not mushy. Drain and let cool slightly.

In a separate bowl, whisk together extra-virgin olive oil, lemon juice, sumac, salt, and black pepper until well combined. Set aside.

Once the potatoes are cool, slice them into bite-sized cubes and place them in a large mixing bowl.

Add chopped parsley, diced red onion, diced cucumber, halved tomatoes, black olives, and crumbled feta cheese to the potatoes. Gently mix using a spatula.

Pour the dressing over the potato mixture and toss gently until everything is well coated.

Taste the salad and adjust seasoning if needed before serving.

Allow salad to chill for at least one hour to let flavors meld. Serve at room temperature or chilled, garnished with fresh parsley.