How to explain the British writer Dolly Alderton to an American audience? It might be best to let her work speak for itself — it certainly does! — but Alderton is such a cultural phenomenon in her native England that some context is probably helpful: “Like Nora Ephron, With a British Twist” is the way The New York Times Book Review put it when we reviewed her latest novel, “Good Material,” earlier this year.“Good Material” tells the story of a down-on-his-luck stand-up comic dealing with a broken heart, and it has won Alderton enthusiastic fans in America. In this week’s episode, the Book Review’s MJ Franklin discusses the book with his colleagues Emily Eakin and Leah Greenblatt. Caution: Spoilers abound!