"Right now, we can't talk about anything else," my friend, a foreign affairs reporter in Rome, wrote to me. She wasn't talking about politics, but about pasta carbonara. A few minutes after her message, a New York writer friend told me he was being flown to Rome in a hurry to investigate the topic.

On 23 March, the Financial Times published an article on Italian food expert Alberto Grandi, who claims that the iconic Roman dish was actually invented by Americans. Ever since, there's been an uproar across Italy. "Why is everyone so passionate about it?" I wondered. "And who invented the real carbonara?"