Fermented seeds of the locust bean tree (Parkia biglobosa), are widely used as a flavouring. Known as Iru by the Yorubas and Daddawa by the Hausas (and often misspelt and mispronounced by others as “dawadawa”), it is similar in taste and smell to Thai fish sauce (savoury, salty and pungent). Sold as loose seeds (iru) or…