In northern Nigeria (the Hausa-speaking part) tuwo is the generic word for food in the form of a starchy blob (could be cassava, yam, maize, etc.). This type of food is the major part of most meals in West Africa.
Tuwo is served with what locals call soup. Europeans or Americans tend to think it is more of a stew than a soup. You eat it with your fingers, pulling off a piece and rolling it into a ball then dipping it into the soup. Egusi, bitter leaf and draw soups are all popular throughout Nigeria.
Tuwo is sometimes used as an abbreviation for tuwon shinkafa, which is made from pounded rice. Other similar starchy staples include pounded yam, garri, amala and fufu.