We are back with Balthasar Staindl, and he has an interesting set of recipes for using almond milk jelly as a canvas:

Poured Stars Made from Almonds
ix) Make this thus: pour white almond milk that has been boiled and thickened with isinglass and then cooled into a pewter bowl. Let it gel. Once it has gelled, cut (the stars) into it and pour the stars in white on red, blue, or yellow.
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Poured Flowers
xxi) Item you make poured flowers or estrumb (?) this way. Take white almond (milk) strengthened with isinglass into a bowl. When it has gelled, cut flowers or plants (gewechs) into it, take out the same, and pour in a different colour in its place.
Poured Coats of Arms
xxii) Make poured coats of arms this way: Pour the field colour (veldung farb) into a bowl, then cut out the helmet and pour in its colour.
The recipes emphasise variety, but the principle is the same in all: Almond milk jelly is poured into a bowl to make a wide, flat surface. Once it has gelled, a design is cut into the top and filled with jelly in different colours. I have no way of knowing how elaborate these pieces could get, but there is every reason to think they were as ambitious as cooks could make them. We have already covered the method of making almond milk jelly and how to colour it, so this is one dish that should be readily reconstructable. Served in a pweter dish – newly fashionable in the sixteenth century, polished to mirror brightness – it must have looked striking.
Balthasar Staindl’s work is a very interesting one, and one of the earliest printed German cookbooks, predated only by the Kuchenmaistrey (1485) and a translation of Platina (1530). It was also first printed in Augsburg, though the author is identified as coming from Dillingen where he probably worked as a cook. I’m still in the process of trying to find out more.