This is an excerpt from Two Fifteenth-Century Cookery-Books
The original source can be found at the University of Michigan's "Corpus of Middle English Prose and Verse"
ixl - Oystres en grauey. Take gode Mylke of Almaundys, an drawe it wyth Wyne an gode Fysshe brothe, an sette it on the fyre, and let boyle; and caste ther-to Clowes, Maces, Sugre an powder Gyngere, an a fewe parboylid Oynonys y-mynsyd; than take fayre Oystrys, and parboyle hem in fayre Water, and caste hem ther-to, an lete hem boyle to-gederys; and thanne serue hem forth.
Other versions of this recipe:
Ostyrs in Gravy (Thomas Awkbarow's Recipes (MS Harley 5401))
OYSTERS IN GRAVEY (Forme of Cury)
Oysters in gravy (Fourme of Curye [Rylands MS 7])
Oysters in gravy (Enseignements qui enseingnent a apareillier toutes manieres de viandes)
Oystres in grauey (Two Fifteenth-Century Cookery-Books)