Travel: In Sardinia, there is a speciality cheese that you won't find on any restaurant menu or in any shop. It is casu marzu: matured in blocks the size of a human head, and fermented until it is infested with thousands of transparent maggots.
If the maggots are dead, then the cheese is too rotten to eat. If they are alive, then the cheese is cut into thin strips and spread on bread. Diners then hold a hand over the sandwich to prevent the fly larvae from leaping into their eyes.
It is banned, of course. Rotten food tends not to be kind on the stomach. In The Devil's Picnic, Canadian Taras Grescoe does not try casu marzu. Nor does he try ortolan, an endangered songbird, fattened and drowned in Armagnac (a banned French dish enjoyed by the dying François Mitterrand). But as he tours the planet indulging in delicacies that are often found on a list of prohibited substances, he does try several of them. He searches for bull's testicles in Spain (and ends up munching on a pig's instead), drinks Norwegian moonshine and chews on Bolivian coca leaves. He smokes illegally imported Cuban cigars in tobacco-hating California and eats unpasteurised French cheese in a bar until the smell of it drives other customers into the fresh air.
In what must be one of the most innocuous acts of drug trafficking ever, he also smuggles Marks & Spencers poppy seed crackers into Singapore, the recognised world leader in prohibition, where even gold-foil-wrapped chocolate coins are on the banned list lest they be mistaken for the real thing. And finally, he visits the Geneva offices of Dignitas, where the ill come to drink the life-ending pentobarbital sodium. It is the one thing Grescoe hopes never to have to taste.
At first glance, Grescoe's collection of crackers and caffeine and smelly cheeses appear to make up a distinctly weak menu, a thin soup disguised as a hearty meal. Under most other pens it might be, especially given that the genre of travel writing is increasingly cluttered with books in which a single concept is stretched over 250 pages, with the hope that the author's winning personality and the occasional scrape with death will get it gasping to the epilogue.
Thankfully, Grescoe is an assured, entertaining and skilled writer. The Devil's Picnic is definitely a travel book, and Grescoe colourfully and efficiently sketches everything from the dizziness of Bolivian street life to the wretchedness of Oslo's heroin addicts. But the book's strength is in how he uses each mission as a starting point from which to explore the wider theme of prohibition. His Norwegian trek expands into a broader history of alcohol; chewing coca leaves in Bolivia allows him to expound on the US's "War on Drugs"; and his enjoyment of Époisses cheese ("a bit like gnawing on a urinal cake while wading through a feedlot lagoon") is also an investigation into the paranoia over EU food legislation. Ultimately, it develops into a dissertation on the nature of prohibition, on its use as a weapon of power and the strange allure of forbidden fruits.
Grescoe's experiences are obviously central to the overall story - whether it is spacing out on coca leaves, or stubbing out a €65 Cohiba cigar after finally admitting he just doesn't like the taste - but he knows exactly when to stand aside and let the subject expand beyond the expected. It makes The Devil's Picnic almost as rewarding to read as it obviously was for Grescoe to write.
The Devil's Picnic: A Tour of Everything the Governments of the World Don't Want You to Try, By Taras Grescoe, MacMillan, 359pp. £12.99
Shane Hegarty is an Irish Times journalist
