Begin by washing and scrubbing the Yukon Gold or red-skinned potatoes under cold water. Place them in a large pot, cover with cold water, and add a generous pinch of salt. Bring to a boil and cook for 15-20 minutes until fork-tender.

Once the potatoes are tender, drain them in a colander and let cool for about 10 minutes.

In a mixing bowl, whisk together the extra-virgin olive oil, fresh lemon juice, sumac, and season with salt and black pepper to taste.

Cut the cooled potatoes into bite-sized cubes and place in a large mixing bowl.

Add parsley, diced red onion, diced cucumber, chopped tomatoes, and black olives to the bowl with the potatoes.

Pour the dressing over the salad and gently toss to coat.

Taste and adjust seasoning as necessary.

Let the salad sit for at least 30 minutes before serving, garnished with additional parsley.