Preheat oven to 350. Mix together soup, milk, vegetables and chicken and spread into a 9x13 baking dish. Set aside.
In a separate bowl, combine biscuit mix and cheddar cheese and mix well. Stir in cold water and mix just until dough forms. Add dollops of dough on top of chicken mixture.
Bake for 40 minute or until the biscuits in the center of the pan are done, browned and cooked through.
Remove from oven and mix together melted butter and garlic herb seasoning (that comes with the biscuit mix) and use a pastry brush to brush on top of the biscuits. Let stand five minutes before serving.