JT Nesbitt has never met a stranger. He’s a charming and engaging guy, cordial in a relaxed way that probably makes him everyone’s favorite bartender. And he pours a damn fine drink down at Flanagan’s, even if it isn’t the career path he’d originally chosen.

Three years ago, he was a world-renowned custom motorcycle designer dining next to the prince of Bahrain with a million dollar deal on the table and an offer for complete artistic freedom. That same weeke...