Preheat the oven to 425°F (220°C).

In a skillet over medium heat, melt the butter and add the onion and celery. Sauté for about 5 minutes until they are soft and fragrant.

Stir in the flour and cook for 1 minute to remove the raw taste.

Gradually whisk in the chicken broth and milk, stirring constantly until it thickens.

Add the salt, black pepper, thyme, garlic powder, turkey, and frozen peas and carrots to the skillet. Stir everything together.

Roll out your pie crust and place it in the pie pan.

Pour the turkey mixture into the prepared crust.

Cover with a second layer of crust, sealing the edges, and cut slits in the top.

Bake for 30-35 minutes until golden brown.

Let the pie cool for a few minutes before slicing.