According to a magazine article in the August 2000 issue of Scientific American, Blancmange is a dish commonly seen in 16th century France or England. It is "a thick puree of rice and chicken moistened with milk from ground almonds, then sprinkled with sugar and fried pork fat."
Another book, The Medieval Kitchen: Recipes from France and Italy describes a recipe for Blancmange.
Take cooked breasts of chicken and put them on a table and shred them into the finest fibers you can. Then wash the rice and dry it, and make it into flour, and put it throught a sieve; then moisten this rice flour with goat's, sheep's, or almond milk, and boil it in a well-washed and clean pan; and when it begins to boil, add those shredded breasts, with white sugar and fried white pork fat; and keep it away from the smoke, and let it boil gently without excessive fire, so that it becomes as thick as the rice should be. And when you serve it, top it with crushed or pounded sugar, and fried pork fat.