After delivering the closing speech at his bar mitzvah, marking the spiritual journey from boy to man, Byron Lazaroff-Puck turned to America's most famous celebrity chef with a promise."Don't worry," the 13-year-old told his father, Wolfgang Puck. "In a few years, you'll be sipping mai tais in Malibu, and I'll take over.""It was just a joke," Lazaroff-Puck, now 31, tells me. "But the very next day, he came up to me and said, 'If you really want to understand this industry, you have to come work.'"That's how he ended up in the kitchen at Spago, the Los Angeles restaurant that birthed his father's multimillion-dollar empire, when summer break rolled around seven months later.Job title: dishwasher.

Family dinners at home were rare when Lazaroff-Puck (pictured with his father) was young.

Courtesy of Byron Lazaroff-Puck

Eighteen years later, Puck doesn't have time to sip many mai tais — he has 25 fine-dining restaurants and over 1,000 employees to oversee. Still, the 76-year-old isn't doing it alone. Lazaroff-Puck has worked his way up from that three-compartment stainless steel sink to an office he shares with his father.Job title: President of the Wolfgang Puck Fine Dining Group.

When the pair took me behind the scenes of Spago's Beverly Hills kitchen, I wanted to learn how the 44-year-old restaurant has endured in a city chasing everlasting youth. The staff that has stuck around for decades, a sixth sense for anticipating guests' needs, and an embrace of fresh ideas and technology are all ingredients in its recipe for success.The secret sauce, though, is Puck and his son. And making it together has been healing for both of them."Children have this unbelievable sense of wonderment about the world, where everything is new and fun and interesting," Lazaroff-Puck said. "When I work alongside my dad, that's what the world feels like."A star is bornPuck has often said that his restaurants are like his children, which would make Spago, now grossing $15 million annually, Lazaroff-Puck's eldest brother."I didn't get to have the most interpersonal relationship with my dad growing up because he was, you know, building a multinational globe-trotting company," Lazaroff-Puck said.