The noodle is a type of staple food made from some type of unleavened dough which is stretched, extruded, or rolled flat and cut into one of a variety of shapes. While long, thin strips may be the most common, many varieties of noodles are cut into waves, helices, tubes, strings, or shells, or folded over, or cut into other shapes. Noodles are usually cooked in boiling water, sometimes with cooking oil or salt added.