From:
The Thorough Good Cook
Sauces: 26. German Sauce (Sauce Allemande)
To make this
sauce, the remains of the
liquor in which
fowls have been boiled, or
chicken consommé, or indeed anything which has a flavour of
chicken, should be added to an equal quantity of
smooth sauce and set to
simmer till reduced; after which skim, remove the
fat, add the
yolks of two or three
eggs, a piece of fresh
butter of the size of a
walnut, and pass through a
sieve.