Preheat oven to 375°F (190°C). Grease a 9x13-inch casserole dish.
In a large bowl, mix shredded chicken, peas and carrots, cream of chicken soup, milk, salt, pepper, and garlic powder until well combined.
Pour mixture into prepared casserole dish and spread evenly.
Top with biscuit dough pieces, spacing evenly across the surface.
Bake for 25–30 minutes or until biscuits are golden brown and the filling is bubbling.
Let cool for a few minutes before serving.