Shirazi Salad

white wine vinegar

plus 2 Tbsp olive oil

Kosher salt

small red onion, finely chopped

scallions, whites and light greens finely chopped, dark greens thinly sliced and kept separate

Roma tomatoes (1 1/4 lbs), seeded and chopped into 1/4-inch pieces

Persian cucumbers, chopped into 1/4-inch pieces

flat-leaf parsley leaves, roughly chopped

mint leaves, roughly chopped

ground sumac