Combine ground pork, ground beef (or veal), chicken stock, crushed garlic, salt, pepper, ground sage, and allspice in a large saucepan.

Bring the mixture to a boil, then reduce heat and simmer until the meat loses its pink color.

Continue simmering for 30 minutes, uncovered, stirring occasionally.

Stir in mashed potatoes and allow the mixture to cool for at least two hours.

Press the cooled filling into an uncooked pie shell.

Place the top pastry crust on top of the filling and crimp the edges to seal.

Brush the top crust with egg or milk for a golden finish.

Cut a small hole in the center of the top crust to allow steam to escape.

Bake at 425°F (220°C) for 25-35 minutes, or until the crust is golden brown.

Allow the pie to cool and set for at least 20 minutes before serving.

Serve with beef gravy and petite pois (tiny sweet peas).