The recipes are compiled and written in Latin and someone had jotted them down at Durham Cathedral's monastery in the year 1140.
It was essentially a health book, so the meals were meant to improve a person's health or to cure certain afflictions. The other earliest known such recipes dated to 1290.
Many of the dishes sound like they would work on a modern restaurant menu, 'Discovery News' reported.
"According to the text, one of the recipes comes from the Poitou region of what is now modern central western France," Giles Gasper from Durham University's Institute of Medieval and Early Modern Studies said.
Researchers are putting together a translation of the cookbook under the title "Zinziber" (Latin for ginger).