Pasta is a type of food staple usually associated with Italian cooking, made from a dough of hard wheat (durum wheat) and water, sometimes with the addition of egg, or (as colourants) spinach, tomato or squid ink. This dough is then rolled into flat sheets, thin cylindrical strings or tubes, or a variety of traditional shapes such as shells, bows, butterflies, hoops and spirals. It can be cooked fresh, but is more often sold in dried form: it has a very long shelf life. It is high in carbohydrates. Spaghetti is an example of a pasta. It is widely believed that pasta was adapted by the Western world from the Chinese noodle dishes described by Marco Polo.