How to Make It
In a colander or sieve, toss onion slices with salt and let stand for 5 minutes to soften and reduce the harshness. Rinse and drain well.
Transfer the onion to a bowl and toss with parsley and sumac. Serve within 30 minutes.
Recipe adapted from Unforgettable: The Bold Flavors of Paula Wolfert's Renegade Life. Mortar and Pestle Press; $35.