Preheat 350 and grease a 13x9 baking dish. In a bowl,combine thawed vegetetables,chicken,undiluted soup,milk, sour cream,1/2 cup of the cheese, and the old bay seasoning.
Pour into baking dish. Bake uncovered for 20 mins-25 mins.
Meanwhile separate crescent rolls into 4 rectangles. Press perforations of dough. Cut each in half long ways to make 8 strips. Set aside until ready to top in a criss cross pattern. I did a little on an angle.
.After first 20 minutes of baking. Sprinkle the remaining cheese evenly over top. Working quicking I gently layer the strips on top and just made them fit to my liking.( no need to press strips together just overlap slightly) Raise the temp to 360 and bake 15-20 minutes until crescent roll topping is browned. Let casserole sit 5 mins before serving