Preheat oven to 375 degrees Fahrenheit (190 degrees Celsius).
In a large bowl, whisk together the cream of chicken soup, sour cream, milk, garlic powder, onion powder, and black pepper.
Fold in the shredded chicken and frozen vegetables until well combined.
Pour the chicken mixture into a 9x13 inch baking dish and spread into an even layer.
Bake the mixture for 15 minutes to ensure the base is hot.
Remove the dish from the oven and arrange the biscuit dough pieces on top of the chicken mixture.
Sprinkle shredded cheddar cheese evenly over the biscuits.
Return to the oven and bake for an additional 15 minutes or until the biscuits are golden brown and the center is cooked through.
Allow the casserole to rest for 5 minutes before serving.