Place the potato in a small pot of water, bring to a boil, and cook until tender, about 15 minutes, then mash it with a fork and set aside.

In a large skillet over medium heat, combine the ground pork, ground beef, onion, and garlic.

Cook the meat mixture until browned and crumbled, draining any excess fat if necessary.

Stir in the beef broth, cinnamon, cloves, allspice, salt, and pepper, mixing well to combine flavors.

Reduce the heat to low and simmer uncovered for about 20 to 30 minutes until the liquid has mostly evaporated but the meat is still moist.

Stir in the mashed potato to bind the meat mixture, then remove the skillet from the heat and let the filling cool to room temperature.

Preheat your oven to 375°F (190°C) while the filling cools.

Line a 9-inch pie plate with the bottom pie crust and spoon the cooled meat mixture evenly inside.

Place the second pie crust over the top, trim the edges, and crimp with a fork or your fingers to seal the pie completely.

Cut a few slits in the top crust to allow steam to escape and brush the surface with the beaten egg for a golden finish.

Bake in the preheated oven for 40 to 45 minutes, or until the crust is golden brown and flaky.

Remove the tourtiere from the oven and let it rest for at least 10 minutes before slicing to ensure the filling holds its shape.