Sweet and sour beans in sauce. Modern South African “sousboontjies” are made from a speckled bean known as a sugar beans (lima beans). Hettie Claassens describes the interesting history of this traditional South African dish in her book "Die Geskiedenis van Boerekos". Sousbone (sweet and sour beans in sauce) was first made by the Romans, who used vinegar, spices and honey. The 13th century Arabs made a similar dish with sweetened mustart, vinegar and raisins.