For more than 750 years, strict rules have guarded what cardinals can and cannot eat to prevent hidden messages stuffed inside chicken, ravioli and napkins.

This past week, travellers in Rome may have spotted cardinals frequenting their favourite restaurants. Just before the last papal election in 2013, Italian media reported that many of these men were making the time to visit a particular neighbourhood favourite, Al Passetto di Borgo, a family-run eatery located 200m from Saint Peter's Basilica, where Cardinal Donald William Wuerl is known to order the lasagna and Francesco Coccopalmerio (allegedly the most-voted Italian cardinal in 2013) likes the grilled squid.

Cardinals may feel some urgency to get in a good meal or two because, during the conclave beginning on 7 May, in which 135 cardinals will hold a secret election for a new pope in the Vatican's Sistine Chapel, they'll be entirely secluded from the rest of the world for an indefinite period of time. Voting, sleeping and eating all take place in tightly controlled sequestration.

Papal conclaves are notoriously secretive affairs. The cardinals are secured in a single shared space with no messages allowed in or out, except for the smoke signalling whether a vote has been successful. White smoke signals a new pope and black means another vote is required to reach the two-thirds-plus-one consensus required to crown a new pontiff. What precisely occurs in these conclaves is unknown, but one thing is certain: the cardinals must eat over the days or weeks it takes to elect the new leader of the world's 1.4 billion Catholics.

But with provisions going in and out, how is the secrecy of the conclave maintained? How can the cardinals ensure the integrity of the vote, unaffected by outside opinion?

Historically, food has presented a potential risk: a cardinal's ravioli might be stuffed with an illicit message from the kitchen staff; or a cardinal could sneak a vote update to the outside world with a dirty napkin. However, communal eating is also one of the contexts in which furtive negotiations can take place. Recent pop culture representations have made the most of this, using conclave food culture to create a heightened sense of suspicion, intrigue and control.

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Take the 2024 film Conclave, where almost all the plot points occur not in the voting chambers, but in the cafeteria. The noisy meals contrast with the almost entirely silent conclave proper, which proceeds without formal debates. The otherwise silent voting is only sparingly punctuated by moments of ritual speech, like the audible oath a cardinal takes as he drops his voting card into the ballot urn. Still,........

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