This is an excerpt from Le Viandier de Taillevent
(France, ca. 1380 - James Prescott, trans.)
The original source can be found at
James Prescott's website
Sauce for keeping saltwater fish. Take bread, parsley, sage, avens, vinegar, ginger, cassia flowers, long pepper, cloves, grains_of_paradise, saffron powder and nutmeg. When everything is strained it should be bright green. Some add the avens including the root. (BN manuscript, p. 33.)