Heat the oil in a heavy saucepan, add the onion, and cook over medium heat until it is translucent. Add the meat and continue to cook, stirring occasionally, until it is lightly browned on all sides.
In a small bowl, mix the peanut butter with the cold water and pour it over the meat. Dilute the tomato paste with the hot water, pour the liquid over the stew, and stir well to make sure all the ingredients are well mixed. Add the remaining ingredients, lower the heat, cover, and cook, stirring occasionally, for 1 hour, or until the meat is tender. Remove the thyme sprigs and bay leaves. Serve hot over white rice.