Following his Broadway debut opposite Nathan Lane in “The Nance,” Jonny Orsini BS ’07 is back in the cast of one of the theater season’s hottest productions. “Fish in the Dark,” by Larry David (“Seinfeld,” “Curb Your Enthusiasm”) stars “Seinfeld” cast member Jason Alexander and runs through July 18 at the Cort Theatre. Discover where it all began (in Boston) for this rising star.