Blanch the following spices: parsley, tarragon, chives, chervil (parsley and chervil in equal proportion and about half as much of the two others, about two handfuls altogether), drain dry and put them in a mortar with the anchovies, shallot, capers, pickled cucumber, butter, yolks, and juice. Pound the whole well together, then add the essence of spinach, mix well, mash through a sieve, and use.
This butter is excellent to decorate and to eat with cold fish. It is sometimes used with cold birds.
Hand-Book of Practical Cookery (1884).