When the meat has lost its raw color, stir in the stock, savory, sage, pepper, cinnamon, cloves, nutmeg and 1 tsp salt. Simmer uncovered for about 15 minutes, until most of the free liquid has evaporated.
5 Stir in about 1/2 cup mashed potato. The potato isn't supposed to make it taste like shepherd's pie; it binds the meat juices and gives the filling its characteristic cohesive texture. Stir in parsley and taste for salt.
6 Cool the filling completely.
7 Line a 9-inch pie plate with pastry. Add the cooled filling and gently level it without packing it tightly. Add the upper crust, seal and crimp the edges, and cut several steam vents. Brush with egg wash.
8 Bake at 425°F for 15 minutes, then reduce to 375°F and bake another 35–45 minutes, until deeply golden.
9 Let stand at least 15 minutes before slicing.