This is an excerpt from Ouverture de Cuisine
(France, 1604 - Daniel Myers, trans.)
The original source can be found at
MedievalCookery.com
Boiled Potato. Take well washed potato, & put it to boil in water, when cooked it must be peeled & cut into slices, melted butter thereon, & pepper.
Other versions of this recipe:
Another Tartoufle (Ouverture de Cuisine)