The author Jonathan Coe, seeking to add a bit of contemporary colour to his novel Expo 58, sends his protagonist to a trattoria in Soho for lasagne, chianti and a bowl of creamy, coffee-spiked tiramisu — a classic Italian dessert that was the height of sophistication in postwar London.

The only problem, as Coe discovered when he was corrected on the point by a ‘very polite’ Italian journalist during an interview, was that the book was set in 1958, and tiramisu wasn’t invented until 1959. Or perhaps it was the early 1970s. As is so often the case with much-beloved dishes, the origins are as hotly disputed as the recipe.