IN a cosy workshop in Eldoret in western Kenya, Jackton Onyango Otieno, a down-to-earth, 62-year-old mushroom expert is completely engrossed in the delicate art of preparing a proper mushroom substrate. Around him is huddled a group of eager youths, taking in his every word. Judging by the regular smiles, Otieno's energy and passion for sharing his expertise is infectious and he clearly finds joy in sharing his expertise and nurturing the next generation of mushroom enthusiasts. Despite the sense of jollity in the workshop, however, there's a deadly serious reason why Otieno is keen to disseminate his knowledge as widely…