This is a dish from Martino, a 15th century writer who was the first to provide more detailed recipes with quantities. My version is from Great Cooks and Their Recipes by Anne Willan. This is a fun book with a lot of early recipes and redactions. I've used several to good effect.
It's pretty much like modern risotto except that egg yolk is used as the thickening agent rather than cheese. There is a problem to work out with the dish. It calls for the use of egg yolks to be added after the rice is cooked. Presumably the heat from the finished dish cooks the egg... but I'm not sure I have the nerve to do this for a feast. I'm not a worrier about undercooked eggs, but I'm cooking for a lot of people here, and one must not screw around. (I'll try it for myself - perhaps I'll have more confidence in the procedure after I see it in action.)
So, there are a couple of options. First, a pasteurized substitute might work, I'll have to try it. Second, I could cheat and use cheese. And third, I could punt and substitute another rice dish. I had an urge to use one of my favorites, Lemonwhyt, from Fabulous Feasts, but I use it all the time, and it seemed like a good idea to try something different.
I recommend both books. For critics of Fabulous Feasts, see my earlier post on Madeleine Pelner Cosman.