Cook 800 g (1¾ lb) skinned broad beans in 1 litre (1¾ pt or 4½ U.S. cups) water with 2 sprigs of savory and 18 g (⅔ oz) salt. Drain off the beans and reserve 30 small halves of the beans as garnish. Pound the remainder of the beans and mix together with the reserved cooking liquid. Pass through a fine sieve and adjust the consistency by thickening with 30 g (1 oz) arrowroot mixed into 5 dl (18 fl oz or 2¼ U.S. cups) cold milk. Bring to the boil then pass through a fine strainer. Finish at the last moment with 150 g (5 oz) butter and add the reserved garnish of broad beans.
This soup may also be prepared as a Cream or a Velouté.