IT has been 40 years since Dorah Sitole walked into Canned Food Advisory Service, the marketing division of a container and packaging company called Metal Box, to interview for the position of cooking demonstrator. Her husband told her about the job opening, saying, “I don’t know anyone who cooks better than you.” That moment would launch her groundbreaking career in food and Sitole’s new book is a reflection on this long career that has shaped the path of South African food culture.  “It’s 40 years of my professional career,” says Mam’ D, as Dorah Sitole is affectionately known, a week…