2 tablespoons butter
1 yellow onion, diced
2 cloves garlic, minced
2 large carrots, diced
2 stalks celery, diced
¼ cup all-purpose flour
¼ cup dry white wine
2 potatoes, peeled and diced
1 cup frozen peas
1 bay leaf
2 cups cooked and shredded turkey
Salt and pepper
3 cups chicken stock
¼ cup full-fat milk or cream
1 teaspoon parsley, fresh or dried
2 sheets frozen puff pastry, thawed
1 egg, beaten
Add the butter to a large, heavy-bottomed saucepan and place over a medium-high heat. Once the butter has melted, add the onion, celery, garlic and carrots. Cook until vegetables start to soften, about 5 minutes.
Add the flour and stir, cooking for one additional minute.
Deglaze with the white wine, scraping all the fond off the bottom of the pot and whisking well to ensure all of the flour is incorporated.
Add the potatoes, peas, bay leaf, turkey, salt and pepper, and then slowly add the chicken stock while whisking, followed by the milk or cream. Stir everything well and lower the heat to medium, simmering until the sauce begins to thicken, about 10 minutes. Add the parsley and remove from the heat.
Preheat the oven to 375 F.
On a lightly floured surface, roll out your puff pastry and cut a circle large enough to cover the bottom of the pie dish, with about a quarter of an inch extra. Carefully transfer the chicken mixture into the pie dish on top of the pastry dough, and top with another circle of pastry dough. Fold the extra crust over the top and press the edges together with your fingers or a fork. Prick some holes in the pastry lid to allow steam to escape, and brush the entire top of the pot pie with an egg wash.
Bake the pot pie until golden brown on top, about 20-30 minutes. Allow to cool at least 5 minutes before serving.