Leeks have the flavour characteristics of onions but without their potency. Therefore, leeks are often more appropriate in stews and soups than onions. Leeks are a decent vegetable and can be braised, served in sauces, au gratin and are a key ingredient in the Scottish cock-a-leekie. Welsh onions come from Siberia, and are small, leek-like bulbs with a delicate flavour. Welsh onions can be used to flavour stews.
Dowell, P., Bailey, A. (1980) The Book of Ingredients, Dorling Kindersley. ISBN 0718119150.