John Onyango has never been to culinary school, nor did he start his career as a chef in a recognized restaurant or hotel. Instead, he first cooked in a suburban food kiosk, where he served the wage earners who worked in the neighboring schools, market and local Nairobi City Council offices.But that was 25 years ago. Today, Onyango is a sought-after chef, cooking for K’Osewe Ranalo Foods. In the business district of Kenya’s capital city, the restaurant specializes in indigenous and African dishes. However, its clientele is the city’s upper…