Preheat the oven to 375°F (190°C).
In a large saucepan, melt the butter over medium heat.
Add the milk, chicken soup, and chicken stock; stir until well combined and heated through.
Stir in the shredded chicken and frozen mixed vegetables; cook for 5 minutes until vegetables are slightly tender.
Pour the chicken and vegetable mixture into a greased 9x13 inch baking dish.
Prepare the Cheddar Bay biscuit mix according to package instructions, using chicken stock or milk as directed.
Drop spoonfuls of biscuit dough evenly over the chicken mixture.
Bake uncovered for 25-30 minutes, or until the biscuits are golden brown and cooked through.
Remove from oven and sprinkle with fresh chopped parsley if desired.
Let cool slightly before serving.
