Home › Soups Without Stock › Leek and Potato Soup
Leek and Potato Soup
1 bunch leeks 1 cup celery 2½ tablespoons butter 1 quart milk 2½ cups potatoes 2 tablespoons butter 2 tablespoons flour Salt and pepper
What survives here is the ingredient list; the method that would have followed in the book is absent, so the proportions are the useful part. They describe a standard milk-based purée thickened with a white roux, which is how the Boston Cooking School handled every soup in the "without stock" chapter.
- The missing methodA plausible reconstruction -- nothing of the original method survives. On these proportions one would sweat the sliced leeks and celery in the 2 u00bd tablespoons of butter, add the diced potatoes and just enough water to cover, and cook until soft; press through a sieve, add the scalded milk, and bind with a roux made from the remaining 2 tablespoons each of butter and flour.
- A bunch of leeksAn imprecise measure; three to four leeks, somewhere around a pound untrimmed, is a reasonable reading, which in modern terms is roughly two large supermarket leeks.
- White parts onlyThe list gives no guidance, but the usual practice for a pale milk soup is to use the white and pale green and keep the tough dark tops for stock; the dark tops will tint the soup and add a coarser note.
- GritLeeks are grown hilled up in soil and trap sand between the layers. Split them lengthwise and wash under running water before slicing; sand does not settle out of a purée.
- Potatoes2 u00bd cups diced is roughly u00be lb to 1 lb. A mealy baking potato breaks down and thickens on its own; a waxy one will stay in pieces and leave the soup thin unless it is pur u00e9ed thoroughly.
- The rouxTwo tablespoons of flour to a quart of milk is a very light binding, thinner than a standard thin white sauce, with the pur u00e9ed potato doing much of the thickening. Cook the butter and flour together a minute or two before adding liquid, and add the milk hot to avoid lumps.
- Don't boil the milk soupOnce the milk goes in, hold it below a simmer. A hard boil will catch on the bottom of the pan and scorch, and the flavour of scorched milk cannot be removed.
- YieldRoughly two quarts finished, serving six as a first course or four as a main with bread.
Soups thickened with milk and a butter-flour roux rather than meat stock answer a practical problem of the period household: stock required a stockpot kept going for hours, while milk, butter and root vegetables were on hand daily. Leek and potato is among the plainest of the family, a peasant combination found across northern Europe long before it was written down; the chilled cream version popularised as vichyssoise in New York hotel dining rooms in the early twentieth century is a descendant of the same pairing. The celery here is doing the work that a stock would otherwise do, supplying the savoury background note.