This is an excerpt from Du fait de cuisine
(France, 1420 - Elizabeth Cook, trans.)
The original source can be found at
David Friedman's website
49. And to give you to understand how you make the cold sage arrange that you have a great deal of parsley, a great deal of sage, and let them be well cleaned and washed and drained and brayed very well, and bray such a great quantity of it that it may be thoroughly green; and when they are well brayed mix them and put them with your bread [see recipe 48]. And then take your spices, that is white ginger, grains of paradise and pepper and strain all this, and season with vinegar and strain it to be very thick. And when your meat is well cooked take it out onto fair boards and fair and clean tables, and then separate the meat, that is the poultry in one place and the pieces of piglet in another, and such that when it comes to the sideboard you put in each dish four pieces of the said meat, that is a quarter of poultry and a little piece of the said pork on top in half of each dish, and as much in the other part; and in each dish on one part put calaminee and on the other part next to it put cold sage. And then take the egg whites and cut them into little dice, then scatter onto the said dishes onto the cold sage; and sugar-spice pellets on the calaminee.
Other versions of this recipe:
Sauge Seynes (Liber cure cocorum [Sloane MS 1986])
Cold Sage [Sauce] (Le Viandier de Taillevent)
Cold sage soup of halves of young chickens and little geese (Le Menagier de Paris)