Raw red onions are marinated with salt, sumac and lemon juice. Then it is combined with chopped parsley.
If the onions you use are bitter, sprinkle a little salt over the thin slices and soak them in cold water for 1-2 minutes. Gently squeeze them and drain. This step will remove the bitterness.
Find it online: https://www.giverecipe.com/onion-salad/