Leek soup, or usually leek and potato soup, is common to the cuisines of many places. It is made from leeks and other vegetables simmered in water or stock. Potatoes are usually included, and other ingredients may include onions and garlic. The soup may be enriched with milk or cream before serving. It is usually served hot, but if chilled may form the basis of vichyssoise.
Leek soup is a traditional staple of many cuisines. A 1771 reference book lists the Italian , "a leek-soup or pottage". A Scottish cook, Susanna MacIver, included leek soup in her 1782 Cookery and Pastry; a Welsh version, â "leek pottage or porridge" â is recorded in 1794; a German-English dictionary from 1796 refers to , "leek pottage". Maria Rundell's Domestic Cookery (1808) gives a recipe for "Scotch Leek Soup", thickened with oatmeal.
French leek and potato soup has the alternative names (in honour of the man who popularised potatoes in France) and . Elizabeth David (1984) refers to "every French housewife's potato and leek soup". is a Basque leek soup, typically using the same ingredients as the versions from elsewhere. In Spain the soup is known as .
Leeks are the one ingredient common to all recipes. In some recipes only the white part of the leek is used; in others, both white and green are used. Potatoes are also usually included. Cooks and food writers differ about the other ingredients.