Combine milk, stock and corn starch in a medium saucepan. Bring to a boil over medium high heat and boil for 1 minute, stirring constantly. Stir in the the Herb Roasted Mushrooms, Chicken & Vegetables and heat until hot. Spoon mixture into a 1 1/2 quart casserole dish. Cut each raw biscuit in half. Arrange cut biscuits, cut side down, over hot chicken mixture, covering it completely. Bake until mixture is bubbling and biscuits are golden brown, about 20 minutes.