Suya comes from the Hausa north, from Kano and Kaduna, but now every Nigerian city has a mai suya grilling beef over charcoal by the roadside once the sun goes down. Thin slices of beef are threaded onto skewers, rubbed with yaji, a fiery mix of roasted peanut powder, chilli, ginger and stock spices, and grilled until charred at the edges. It comes wrapped in newspaper with sliced raw onion, tomato and extra yaji for dipping. The common mistake is cutting the beef thick; it needs to be thin enough to see light through, so it cooks fast and stays tender. Chef's tip: put the beef in the freezer for 30 minutes first, and it will slice wafer thin with ease.