Position rack in middle of oven. Preheat oven to 350°F/180°C. Coat a 9-inch (23 cm) pie plate with nonstick spray; set aside.

Roll out one disc of pie crust to a 12-inch (30.5 cm) round (about 1/4-inch/6 mm thick) and fit into prepared pie plate; trim edges to create a 1-inch (2.5 cm) overhang. Arrange sliced turkey in an even layer on the bottom of the crust. Drizzle with about a third of the gravy. Spread an even layer of the mashed potatoes on top, then top with an even layer of the cooked greens, the cranberry sauce and then a thick layer of stuffing. Press down gently to compress all the layers. Drizzle with remaining gravy.

Roll out the remaining disc of dough to a 13-inch (33 cm) by 1/4-inch thick (6 mm) round and fit on top of the pie. Trim edges, seal with bottom pastry, fold both under and crimp decoratively. Make steam vents in top pie crust and brush crust with beaten egg.

Bake pie for at least 40 minutes or until golden brown and steaming. Let pie sit for 5 minutes before serving.