The Romans introduced the onion to Britain and, in the New World, American Indians added a highly pungent wild onion to their stews. Onions are used widely in cooking. They add flavour to such dishes as stews, roasts, soups, and salads, and are also served as a cooked vegetable. The onion's characteristic pungency results from the sulfur-rich volatile oil it contains. Release of this oil during peeling brings tears to the eyes, but many cooks claim that tears can be avoided by peeling onions under running water.
Onions vary in size, shape, colour, and pungency.
Warmer climates produce onions with a milder, sweeter flavour than do other climates. Globe-shaped onions may be white, yellow, or red. They have strong flavour and are used chiefly for soups, stews, and other prepared dishes and for frying. Bermuda onions are large and flat, with white or yellow colour and fairly mild taste. They are often cooked and may be stuffed, roasted, or French-fried.