Onion — Many plants in the genus Allium are known by the common name onion but, used without qualifiers, it usually refers to Allium cepa. Allium cepa is also known as the ‘garden onion’ or ‘bulb’ onion and ‘shallot’.
Onions, as one of the oldest vegetables known to mankind are to be found as an ingredient in a bewildering array of recipes and preparations, spanning almost the totality of the world’s cultures; they are nowadays available in fresh, frozen, canned, pickled, and dehydrated forms. Onions can be used, usually chopped or sliced, in almost every type of food, including cooked foods and fresh salads, and as a spicy garnish; they are rarely eaten on their own but usually act as accompaniment to the main course. Depending on the variety, an onion can be sharp, spicy, tangy and pungent or mild and sweet.
Onions pickled in vinegar are eaten as a snack. These are often served as a side serving in fish and chip shops throughout the United Kingdom. Onions are a staple food in India, and are therefore fundamental to Indian cooking. They are commonly used as a base for curries, or made into a paste and eaten as a main course or as a side dish.
Evidence suggests that onions may be effective against the common cold, heart disease, diabetes, osteoporosis, and other diseases. They contain anti-inflammatory, anticholesterol, anticancer, and antioxidant components such as quercetin.