Paul Thomas Anderson first made a splash in Hollywood with his film “Boogie Nights,” a portrait of the porn industry that burgeoned in the San Fernando Valley, the much-mocked suburbs of Los Angeles. Anderson is a Valley native, and proud to live there still. “There was a terrific story right in my own back yard,” he told David Remnick. “I guess at some point, I probably read ‘Write what you know.’ I was, like, Well, that’s a good place to start.” Many of Anderson’s films—such as “Magnolia,” “There Will Be Blood,” and “Inherent Vice”—tell stories from Southern California’s past and present. Anderson’s new film, “Licorice Pizza,” returns to that terrain. It portrays the thorny relationship between a teen-aged boy and a twenty-five-year-old woman, and the pair’s misadventures in the Valley of the mid-seventies. Anderson, who could recruit any stars in Hollywood, instead cast two newcomers as his leads: Alana Haim (a musician in the indie band HAIM) and Cooper Hoffman. Anderson spoke to David Remnick from his home in—where else?—the Valley.