Begin by Melting Butter over low heat in a 12-inch Cast Iron Skillet.
When the butter starts to bubble, add the celery, carrots, and onions that you prepared and stir to cover in the butter.
Continue to cook the Mirepoix over low heat, sweating the vegetables for about 15-20 minutes.
Sprinkle a layer of Montreal Seasoning over the top and mix.
Add flour and constantly stir to cover vegetables, ensuring you do not burn the flour mixture.
Slowly begin to add milk and continue to stir to avoid clumping.
Begin to pour in chicken stock and continue to stir slowly.
Add the peas, corn, and turkey.
Season with a little more Montreal Seasoning and Black pepper, and give it one last stir.
Preheat the oven to 425°F.
Using a pizza cutter, cut the first pie crust into strips, brush it with egg wash, and place it on top of the Pie filling.
Repeat step eleven with the second pie crust, but now you will be weaving it into the first crust.
Place the pie in the preheated oven and bake for 45 minutes or until the top has browned and it has begun to bubble through the openings.
Slice and serve as is or with a side of mashed potatoes.