Wash and scrub the Yukon Gold or red-skinned potatoes under cold water. Place them in a large pot, cover with cold water, and season with a pinch of salt. Bring to a boil.

Once boiling, reduce heat to medium-low and simmer for 15-20 minutes until tender but not falling apart. Drain and set aside to cool.

While the potatoes cool, whisk together olive oil, fresh lemon juice, sumac, salt, and black pepper in a mixing bowl.

Once cool, cube the potatoes and add them to a large mixing bowl.

Add chopped parsley, diced red onion, cucumber, halved tomatoes, black olives, and crumbled feta to the potatoes.

Pour dressing over the mixture and gently toss until everything is well-coated. Be careful not to mash the potatoes.

Taste and adjust seasoning as desired. Let rest for about an hour before serving or chill in the refrigerator.