Chop Parsley: Wash and thoroughly dry the parsley. Chop it finely (but not into a mush).
Mix Ingredients: In a bowl, combine parsley, cucumber, onion, and any optional add-ins.
Season: Sprinkle with sumac, drizzle with lemon juice and olive oil, and season with salt.
Toss & Taste: Mix well and taste for balance. Add more lemon or sumac as desired.
Serve: This salad is fresh and bright on its own or as a topping for grilled meats or falafel.