Preheat your oven to 425°F (220°C).
In a large skillet, melt butter over medium heat and add onions.
Cook onions until translucent, then add carrots and peas.
Add shredded chicken and mix well.
Pour in chicken broth and heavy cream; stir to combine.
Season with salt, pepper, and thyme.
Roll out one pie crust and place it in a pie dish.
Pour the chicken mixture into the crust.
Cover with the second crust and cut slits in the top.
Bake for 30-35 minutes until golden brown.