Onion is the largest vegetable produced and consumed not only in India but also in the world. Although, it is classified as vegetable, it is mainly used in cuisines and culinary preparations. Onion is believed to have originated in Asia, though it is likely that onions may have been growing wild on every continent. Dating back to 3500 BC, onions were one of the few foods that did not spoil during the winter months. Onions grew in Chinese gardens as early as 5000 years ago and they are referenced in some of the oldest Vedic writings from India. In Egypt, onions can be traced back to 3500 B.C.