Ken Oringer celebrated the 15th anniversary of Clio in style Tuesday with a 15-course alumni dinner attended by a slew of well-known chefs, all of whom have a connection to the restaurant. Among those jockeying for space in the Clio kitchen as they cooked conceptual dishes like caviar and ice cream were Tony Maws of Craigie on Main, Alex Stupak of Empellon, Alex Talbot and Aki Kamozawa of Ideas in Food, Sam Gelman of Momofuku, John Paul Carmona of Manresa, Doron Wong of China Grill, and Chris Chung of AKA Bistro, among others.