Riddles in Leonardo da Vinci's Last Supper were the basis for the plot of the best-selling novel The Da Vinci Code, but why hasn't anyone cracked the code of what food was served at the legendary dinner party?

New research by John Varriano suggests that the meal being consumed was neither bread nor pascal lamb, as once thought. Instead, he writes in a new article in Gastronomica that the 1997 cleaning and restoration of the fresco revealed plates of grilled eel garnished with orange slices. Above is a detail of the section of the painting in question (with my best effort to identify and highlight the dish). I have to admit the evidence is a little murky to my untrained eye, but I'll take Varriano's word for it. He zooms in for a much closer look in the article.

Pairing fish with oranges was trendy at the time The Last Supper was painted, according to Varriano, who notes that a recipe for grilled eel appears in Platina's On Right Pleasure and Good Health, an influential Renaissance cookbook. He also loosely ties the choice of the dish to Leonardo's own grocery lists, preserved from 1400s, which indicate he shopped for "peppered bread, eels, and apricots" at least a dozen times.

At Supper with Leonardo (PDF) [Gastronomica]