HEAT oven to 400°F.
TOSS meat with flour in 13x9-inch baking dish. Stir in vegetables. Mix broth and dressing until blended; pour over meat mixture.
BAKE 1 hour or until meat is done. About 10 min. before the end of the casserole baking time, unfold pastry sheet on lightly floured surface and roll out to 13x9-inch rectangle.
TOP casserole with cheese; cover with pastry. Bake 15 to 20 min. or until golden brown.