Tourtiere (Meat Pie) - cooking recipe

Ingredients

Meat Filling
1 1/2 lbs ground pork
3/4 cup finely chopped yellow onion
1/4 teaspoon ground allspice
1/4 teaspoon ground cloves
1/2 teaspoon kosher salt (to taste)
1/8 teaspoon fresh ground black pepper
3/4 cup water, plus additional if needed
1 lb russet potato
Crust
2 1/2 cups all-purpose flour
3/4 teaspoon salt
3/4 cup cold unsalted butter, cut into 1/2-inch cubes (1-1/2 sticks)
1/2 cup ice water, plus additional if needed
Egg Wash
1 egg yolk
1 teaspoon water

Preparation

Put pork, onion, allspice. cloves, salt, pepper, and 3/4 cup water into a wide, heavy pot. Break up meat with a spoon, then cook over high heat until water starts to boil. Cover and simmer on low heat for 1 hour. If mixture becomes dry, add a few tablespoons of water as needed.
Make pie crust while filling is cooking. Stir together flour and salt. Cut butter into flour mixture using a pastry cutter, or pulse butter and flour mixture in a food processor, until butter is the size of small peas. Stir in 1/2 cup ice water. Dough should look shaggy and come together when pressed into a ball. If it's too crumbly, add water by the tablespoon until dough just holds together but is not wet or sticky.
Divide dough in half. Flatten each half into a disk, wrap in plastic, and refrigerate.
After filling has cooked for 1 hour, peel and cut potatoes into 1/2-inch pieces. Stir potatoes into meat mixture. If mixture is dry, add 1/4 cup water. Cover and simmer over low heat for 30 to 35 minutes, until potatoes are tender. Uncover and cook off any excess moisture.
Remove from heat. With potato masher, mash potatoes into meat. Set aside to cool to room temperature, 20 to 30 minutes.
While filling is cooling, preheat oven to 425 degrees. Roll out both disks of dough. Line a 9-inch pie plate with one crust. Trim excess dough from edge. Refrigerate both crusts until ready to fill.
Prepare egg wash. In a small bowl, mix egg yolk with the water. Spoon cooled filling into bottom crust, pressing firmly. Brush crust edge with egg wash, then top with remaining crust, crimping edges to seal. Brush top of pie with remaining egg wash. Cut four 1-1/2-inch slashes onto top of crust. Bake in lower third of oven until crust is golden, 30 to 40 minutes. Serve hot or at room temperature.