Rub and work sumac and the salt into the onion slices with your hands really well (this will soften the onions and help spices infuse in well).
Stir in the chopped tomatoes, parsley and paprika flakes, combine well.
Wisk together the extra virgin olive oil and lemon juice and pour over the piyaz salad. Season with more salt (if needed) and freshly ground black pepper.
Serve Piyaz Salad with feta cheese, olives and/or hummus for a delicious spread. Piyaz Salad is also the ultimate accompaniment of Lahmacun and Turkish meatballs, kofte.
