Preheat the oven to 425°F (220°C).

In a large skillet, melt the butter over medium heat. Add onion, carrots, celery, and sauté until tender, about 5 minutes.

Sprinkle the flour over the sautéed vegetables, stirring constantly for about 2 minutes.

Gradually whisk in chicken broth and milk, cooking until thickened and bubbling, about 3-5 minutes.

Stir in the shredded chicken, peas, corn, salt, pepper, garlic powder, and thyme.

Roll out one pie crust and fit it into your pie dish.

Pour the chicken mixture into the prepared crust and spread it evenly.

Top with the second pie crust, seal the edges, and cut slits to allow steam to escape.

Bake for 30 minutes until the crust is golden brown.

Let the pot pie cool for a few minutes before serving.