There is an interesting, but rather crowded recipe in the collection that described how to turn fish – nothing less than the noble pike, too – into moulded show dishes:
33 Roast Pike
Take pike or other large fish, remove their skins raw and take out the bones as well. Chop the flesh (das gebrät) small, spice it, and press it in a carved mould (ain Ingraben form) if you please. It can be shaped like fish or partridges or other things. Boil it in these (moulds). Afterwards, remove it from the mould and roast it on skewers or otherwise. Then slice long pieces like bacon from the fish and lard it like you do a real roast, except that you add some crumbs of white bread. Use two wet knives to pat it into shape like a loaf and boil it in a pan. Then roast it on a spit as is described above.
These instructions also have parallels, in this case both in the Rheinfränkisches Kochbuch and Meister Hans. The Rheinfränkisches Kochbuch divides them into two recipes, but has recognisably similar wording:
3 If you would have partridges in Lent, take two carved pieces of wood in the shape of a partridge and take fish and take away their skins and bones and chop them very small and season them well and press them into the moulds and boil it with that. Thus it takes on the shape of a partridge and you shall roast it afterwards and lard it with pike, thus you have a roasted partridge and a strange dish.
You may also put that into whatever moulds you wish and you may also put it into the guts, bladders and stomachs of fish.
4 If you would make fried struben (= strauben, normally a type of fritter, here it looks like a roast) of fish, take whatever fish you would and take off their skin and bones and chop the fish small and grate into them a crumb of bread and season it well and push it together on a flat surface (strijch iß… czu samen) with a wet knife in the shape of a loaf and lay it into the pan and boil it. Then shape it like struben and put it on a spit and lard it with roasted pike (pieces)
Meister Hans describes the same technique, but uses clearly different wording:
Recipe #110 Aber von Repphünern mach die also
Again of partridges, make them thus
Item first of roast partridges for Lent: Order two moulds carved into wood shaped like partridges, so that when they are pressed together they have the form of a partridge. Take fish and remove the bones and scale them and chop them small. Season it very well and boil it well with the wooden moulds (on?). That has the shape of a partridge. Stick it on a spit and roast it, and lard it with roast pike.
These are not the only instances of shaping chopped fish into just about anything. It seems to have been a fairly common Lenten conceit. In the Mittelniederdeutsches Kochbuch (#25), something broadly similar is done with crawfish. Of course fresh fish of any kind always was a luxury item in itself so these things would have conveyed status. I feel reminded of the way Easter lambs and bunnies are baked in two-part moulds today, a survival of a much older and more varied tradition. And yes, this is absolutely also from where we get gefilte fish.
Bound together with medicinal, veterinary, and magical texts, the culinary recipes of Munich Cgm 384 were partly published in 1865 as “Ein alemannisches Büchlein von guter Speise“. The manuscript dates to the second half of the fifteenth century. My translation follows the edition by Trude Ehlert in Münchner Kochbuchhandschriften aus dem 15. Jahrhundert, Tupperware Deutschland, Frankfurt 1999, which includes the first section of recipes not published earlier.