In a medium pot of boiling water, cook the sweet potato and taro until they are cooked.
Meanwhile, heat the olive oil in a large pot over medium to high heat. Sauté the garlic and ginger with the ground coriander and cayenne for 1 minute.
Add the onion and sauté for a few minutes longer.
Add tomatoes, eggplant and the vegetable stock, simmer for 10 minutes.
Add the zucchini and simmer for 15 minutes.
Drain the taro and sweet potato, mash roughly and add to the stew.
Add the puree and peanut butter, stir well to combine. Simmer for 5 to 10 minutes.
Serve on a bed of cous cous, cooked quinoa or rice or millet. If you wish, roasted peanuts, sliced shallots and dried banana slices.