This Columbia take-out window makes a surprisingly good deli sandwich. There is a complete selection of deli meats, along with soups, pickles, and, of course, potato knishes. (Insider's tip: the Turkey Supreme is loaded with cole slaw, adding a delicious twist to a classic sandwich). So if you find yourself in Morningside Heights on a sunny spring day, stop by Hartley Kosher Deli, sit yourself down on the Low Library steps, and enjoy a lazy college afternoon.