Preheat oven to 425 F
Divide pie dough into 2 parts – one slightly bigger than the other.
Spray a large piece of parchment paper with pan spray.
Roll the larger section out on the sprayed parchment using additional protein powder to prevent the rolling pin from sticking.
Invert the pie crust - parchment and all - over a deep-dish pie plate / deep baking dish.
Carefully peel the parchment away, and press the pie crust into the bottom of the pit pan, carefully working it into the corners.
Fill the lined pie pan with cooled filling, spreading it into the corners and mounding it in the center. Press down slightly to compress.
Spray another piece of parchment paper with nonstick spray, roll out the remaining piece of dough.
Invert the second pie crust over the meat pie filling. Once centered, carefully peel back the parchment, leaving the pie crust in place.
Trim the excess dough and crimp the edges as desired, cut a couple of slits in it for steam vents.
If desired, roll any extra dough very thin, cut into shapes, and apply to the crust for decoration.
In a small bowl or mug, whisk the egg together with a little water. Use a pastry brush to coat the entire top of the tourtière with a thin coating of this egg wash.
Bake in the preheated oven for 30-40 minutes until crust is golden brown.
Serve warm or cold.