01 -
Place thinly sliced red onion in a medium bowl. Sprinkle sumac and salt over the onions and gently massage with your hands for 30 to 60 seconds until the onions begin to soften.
02 -
Pour red wine vinegar or lemon juice and olive oil over the onions. Add chopped fresh parsley. Mix thoroughly to combine the ingredients evenly.
03 -
Cover the bowl and set aside to marinate for at least 20 minutes at room temperature to allow the flavors to develop.
04 -
Stir the onions before serving. Drain off any excess liquid if needed. Serve as a salad, side, or condiment. Store leftovers in an airtight container for up to 4 days.