TATENDA KANENGONI, BIRD STORY AGENCY IT’S shortly after 8 am on a Tuesday, and there's a constant stream of gym-goers and commuters making their way towards a mobile coffee truck parked at a service station in Rolf Valley, an upmarket suburb in Harare.  The unit’s barista, Simbarashe, greets the customers with a smile and, for some, prompts their orders as they approach the truck. One woman drops off a metal flask, asking that it be filled with her "usual.” This energy and culture are replicated in nine other locations in Harare, where Zimbarista coffee units operate, a culture instilled by…