Preheat your oven to 375°F (190°C) and grease a 9×13-inch baking dish.
- In a large bowl, combine the shredded or cubed chicken, frozen mixed vegetables, cream of chicken soup, chicken broth, milk, garlic powder, thyme, salt, and pepper. Stir until everything is evenly mixed.
- Pour the chicken and vegetable mixture into the prepared baking dish and spread it out evenly.
- Tear the biscuit dough into small pieces or leave them whole, depending on your preference. Arrange the biscuit pieces evenly over the top of the casserole.
- Bake the casserole for 25-30 minutes, or until the biscuit topping is golden brown and cooked through. If using, sprinkle the shredded cheddar cheese over the biscuits in the last 5 minutes of baking to melt and brown.
- Let the casserole cool for a few minutes before serving. Enjoy!