Begin by preheating the oven to 425°F.
In a large skillet, heat the butter over medium heat and cook the diced onion and minced garlic until they are soft, which should take around 5 minutes.
Mix the flour in and let it cook for an extra two minutes.
Slowly add the chicken broth, thyme, basil, salt, heavy cream, and pepper, stirring constantly until the mixture thickens, about 5 minutes.
Mix in the shredded chicken and frozen vegetables.
Take one pie dough out of its packaging and place it in a 9-inch pie dish.
Fill the dish with the chicken and vegetable mixture, top with the other rolled-out pie crust, seal the edges, and make several slits in the top to release steam.
Allow the dish to bake for a time span of 25 to 30 minutes in the preheated oven until the surface of the crust turns into a golden brown hue.