Another source (a short one): Recipes from a fragment held in Munich purporting to be “Bohemian and Hungarian”
Item, a carp in blood sauce (fürhess) and a fast day sauce
Item, if the carp is alive, catch the blood and take a spice cake (leczelten). Also take a bread roll (semell) and toast it on the griddle or over the embers, so that it turns brown. Afterwards put it on the fire together in a kettle or a pan, in a good wine, and boil it well. Then pass it through a sieve and take with it a sauce (gescharb) of pears or apples. And put the fish on the fire with all of this, and when it is about to boil up, spice it with cloves, pepper, cinnamon and saffron. And if it turns too sour, sweeten it with honey. When you wish to serve it, taste for the salt in the sauce and salt it to the (proper) point, as is appropriate, so that it is good.
This is not a very unusual recipe for the fifteenth century, though the sauce is rather rich in combining cooked fruit, blood, and bread thickening. If I ever get my hands on a live carp and company willing to eat it, I may just try it out.
Cgm 349b is a manuscript in the collection of the Bayerische Staatsbibliothek München containing a collection of astronomical-astrological and medical texts. It is written on paper and dated on internal evidence to the second half of the fifteenth century. On the last page, a short recipe collection is appended. These recipes were first published and translated into modern German by Trude Ehlert in Ehlert, T. (ed & trsl): Münchner Kochbuchhandschriften aus dem 15. Jahrhundert, Tupperware Deutschland, Frankfurt 1999 on pp. 99-110. I am translating them as I go along. So far, they do not look very unusual.