In a bowl, mix chicken, vegetables, soup, and milk. Roll one of the crusts out to the size of the 9 x 13 baking dish and place in the bottom of the dish. Pour mixture in dish. Roll second crust to 9 x 13 and place on top of mixture. Cut several slits in top crust to allow for venting. Bake at 425 for about 45 minutes or until crust is lightly browned.