Another recipe from the Innsbruck MS:
98 If you would make venison out of beef, take roastable (pratig) (meat) and chop it raw, add eggs, and shape long balls the size of a piece of meat. Let them boil in water in a pan and then prepare a good pepper sauce (pfefferlein) to go over them, or a ziseindel sauce, or a good prülein.
99 But if you would prepare the venison in a sultz (probably aspic), you can also do this well. But you must season it first and then add the sultz (so sultz es), that way it is flavourful inside the sultz. Make the sultz from meat.
Turning less ptrestigious foods into faux venison was a common trope in German recipe collections, and this one has parallels in several other cookbooks (most interestingly in the Mittelniederdeutsches Kochbuch which increasingly looks to be related to the Innsbruck MS). The main principle at work seems to be the way the meat is served – cut into small pieces, roasted, and presented in a spicy sauce. Even cooked egg can be considered credible as ‘venison’ if it is treated this way. It probably makes sense to think of wildprat as a category of dish, much like “hamburger” in our modern world, that can be approximated without the principal ingredient if it is presented correctly. The sultz of the second recipe most likely is an aspic, but there are instances of the word referring to a thick sauce served cold well into the following century so we cannot be entirely sure.
The Innsbrucker Rezeptbuch is a manuscript recipe collection from a South German/Austrian context. It dates to the mid-fifteenth century and survives as part of a set of medical and culinary texts bound together. The editor Doris Aichholzer published it together with two related manuscripts and drew attention to the less elaborate, more practical recipes. The manuscript is of unknown provenance, but has been owned by the Habsburg emperors since at least the early sixteenth century. It is now held at the Nationalbibliothek in Vienna. An edition, German translation and commentary can be found in Doris Aichholzer: Wildu machen ayn guet essen… Drei mittelhochdeutsche Kochbücher, Peter Lang Verlag Berne et al. 1999