Dorothy Hartley, who chronicled the food in England in her well-known book of the same name, was born in Yorkshire in 1893. She trained as a teacher and began teaching in 1920, but was soon writing and traveling extensively on the side. Five years later, she published, along with coauthor Margaret Elliot, her first book, volume one of the six-volume Life and Work of the People of England. Although Food in England was not published until 1954, she lived and traveled during the period in which Downton is set and observed the lives of people all over Britain in that time.
In Food in England, Hartley mentions this striking star tart made with a dozen different jams and includes an illustration, but she provides no recipe for it, explaining only that it was made for church socials on Epiphany. Don’t feel as if you must create such an intricate design. A simple cross and four types of jam—or the six-pointed star and three types of jam— will still be impressive.