Since long before it launched, the El Bulli menu that Grant Achatz's team is serving at Next, was hailed as a completely authentic recreation of Ferran Adrià's fabled cuisine. But maybe, just maybe, Adrià thinks it could be more authentic. "There's lots of people talking about El Bulli, but it closed last July," the chef told the crowd at the inaugural Cancun-Riviera Maya food festival, which opened yesterday. "Now, at present, no one except the people who worked there know what was done there ... We had 500 different dishes," and it's not easy to replicate the experience, he stressed. (Adrià also noted, modestly, that El Bulli's closing "was a national tragedy" in Spain.) Adrià didn't name names, but he did have one piece of advice for all of the attendees: "Do not imitate Ferran Adrià."