The pay-what-you-want restaurant Lentil As Anything has long been famous for caring more about people than about money. But not everyone is supportive of their aim to trade profits for helping those who need it most. Astrid Ryan talks to JASMINE LEUNG about the reluctance of some diners to pay their way, and the impact that's having on the cafes.  The aim is for a place that is "fair, not free," she says.