Pasta sauce peddler Vincent A. Cianci, Jr., the mayor of Providence, believes that a veal cutlet served with a steak knife should be sent back. For veal marsala so tender it can be cut with a fork, and for Sicilian haddock, the mayor heads to The Old Canteen (120 Atwells Ave.; 401-751-5544). Owner Joseph Marzilli, age 81, is a fastidious man who sends his penguin-suited waiters home for two weeks each year so he can apply a fresh coat of alarmingly pink paint to the Fifties-vintage dining room. He expects the same attention to appearance from his customers: Legend has it he once sent John F. Kennedy, Jr., home to change when the young Brown student showed up wearing shorts.