Chicken Pie with Onions and Sumac
This pie with a beguilingly flavorsome filling is a refined interpretation of musakhan, which is of Bedouin origin and is baked in thin Arab bread. It is delicious, and you must try it. It can be made in advance and reheated before serving. Use the large-size sheets of fillo (about 19 inches × 12 inches) that are sold frozen, and defrost for 2 to 3 hours; see page 9 for information about using fillo.