If you read only the title of Charlie Taverner’s book Street Food you could be forgiven for assuming it was an exploration of the stalls that line the trendier streets of our cities, offering bibimbap and bao, jerk chicken and jian bing. But the author’s focus predates brightly coloured gazebo hoardings and polystyrene packaging and looks instead at the working lives of the itinerant traders who populated London before 1900, touting everything from oysters to milk, and what their work meant for a changing capital city.