It has several recipes involving rice at the start:
4 To cook rice
Take thick milk and let it boil. Pick over (klaube) the rice cleanly, and when it has been cleaned (erklaubt), put it into a bowl. Pour boiling water over it and blanch it well, then strain off the water. When the milk is boiling, add the rice and set it into the coals and let it boil until it becomes soft. Then add sugar, and you shall salt it when you wish to serve it.
This is the basic recipe for rice we find in several other sources: clean, blanch, cook in milk until soft. The goal is something like rice pudding, glutinous and very soft. The Meister Hans recipe collection gives very similar instructions a century earlier:
Recipe # 105 Aber von Reiß den mach also
Again of rice, make it thus
Item wash rice nicely in warm water. Pour the rice into a pot and pour water into it (to) a thumb’s width above the rice. Set it down and let it cool. And once you wish to prepare it, pour almond milk into it and set it by a slow fire (auf ein küle – lit. on a coolness) and stir it until it thickens. It will stay as thick as you can manage best.
If you would know whether it is cooked, take the grains between the fingers. If they mash and are not hard, it is done. Serve it with sugar.
The Kuenstlichs und Fuertrefflichs Kochbuch also has a recipe for making a mash of rice flour and almond milk it simply calls Reis:
10 More about Rice (Mehr ein Reiß)
Take rice flour and put it in a pan. Stir it with almond milk like a wheat porridge. Grind blached almonds, as much as the rice flour, but not too small, let them stay coarse. Combine it all, and add a little sugar, let it boil and serve it.
This is very likely meant as a luxurious Lenten dish that mimicked the consistency of thoroughly cooked rice with its coarsely ground almonds. I am not sure why one would not simply boil rice in almond milk, but it must have been attractive to people at the time. Similar dishes are referred to as almond porridge (Mandelmus) in other contexts. The combination of rice and almonds also shows up in different contexts, not least in this piece of decorative cookery:
11 Hedgehog Milk (Ein Igel milch)
Item take rice and boil it in thick milk or in almond milk. Take of blanched almonds, as much as the rice, and grind each separately and then combine them. Grind it well together so that it turns out smooth. Take sugar and also grind it into this, and make it thick. Then put it in a bowl and use a Kümlein (comb?) to shape it like a hedgehog. Shape it artfully (gestaltlich) and pour milk on it so that the hedgehog stands in liquid (in eim pruelein). Thus it is a hedgehog.
Hedgehogs of all kinds feature prominently in fifteenth-century recipe collections, and though 1559 is a little late, there is nothing surprising about this recipe. We frequently meet rice and almonds as a combination in high-class food, not least in the ubiquitous blanc manger. Both ingredients being expensive, but available independent of seasons and, a coveted quality, white made them ideal for high-class cooks to play with.