Scrape the skin from the anchovies, take the flesh from the bones, pound it smooth in a mortar, rub through a fine sieve, put the anchovies into the mortar with the butter, cayenne, grated nutmeg, and mace, beat together until thoroughly blended, mix in the chopped herbs.
If you are going to serve it cold, mould the butter in small shapes, and turn it out.
To keep for later, press the butter into jars, and keep cool.
