Light your Envirofit SuperSaver Charcoal Jiko using little charcoal.
Place onion, peppers, garlic, ginger, cumin, salt, coriander, cinnamon and red pepper flakes in a large sufuria. Pour in water and stir to combine. Mix in sweet potatoes, tomatoes, chickpeas and peanut butter.
Cover and bring mixture to a boil, then close the SuperSaver air regulator slightly to simmer.
Cook until sweet potatoes are tender and stew has thickened. Stir in green beans, cover and continue cooking until beans are heated through.