This is an excerpt from Du fait de cuisine
(France, 1420 - Elizabeth Cook, trans.)
The original source can be found at
David Friedman's website
52. Again, a hot mengier : and to give understanding to him who will make the parti-colored hot mengier, which is also called mortress, let him take pork meat in great abundance according to the quantity which he is ordered to make and clean and wash it very well and put it to cook, and put in salt; and when it is cooked take it out onto fair and clean boards, and remove from it the skin and the bones and then chop it very small. And then take fair bread and put it to soak in your fair beef broth, and with this take spices and put in white ginger, grains of paradise, and pepper - and not too much, and saffron to give it color, and strain it and put in verjuice and put in white wine, and strain this all together and then put it to boil in a fair pot over fair clear coals. And then put the meat to be sautéd in a fair pan with good white lard and sauté it well and skillfully and, this being sautéed, put in a little of the said broth; and then take eggs according to the quantity of the pottage which there is and strain into it the yolks of the eggs to bind it and let them be strained through a strainer. And when this comes to be brought to the sideboard for serving let him make sure that he has a great dish full of powdered cinnamon and beaten sugar in great abundance therewith; and when this comes to the sideboard put your faugrenon in your dish, and with the said powder cover half of the said potage and leave the other half uncovered and thus it will be parti-colored.