Thirty years ago, Jay Rayner sat down for lunch with a Holocaust denier and rising star of the far right. So how did Ewald Althans end up working in the arts and marrying his Taiwanese boyfriend?I sent Ewald Althans a message suggesting we meet in a coffee shop, not far from my East Berlin hotel. I thought it might be a more relaxed place in which to talk. He declined. “I do not feel too comfy any more sitting in a cosy place having an intense talk about National Socialism, Hitler, Auschwitz, etc,” he texted back. “I suggest we have...