No one envied medieval monks for their diets. On the four days a week they didn’t fast, meat was still largely forbidden, barring illness or special occasions. Their one carnal luxury was fish; they made sure to keep plenty on hand. Many abbeys featured early fish farms called stew ponds, where fish could breed, live, and grow into monks’ favorite lunch. With the dissolution of monasteries in the 1500s, many stew ponds were reclaimed by nature. The one at Newstead Abbey, on the other hand, still ripples with the lazy…