Steps
1. Peel, wash and cut cocoyams into pieces and boil until tender but not soft. If cocoyams are overcooked (soft) to facilitate pounding the result will ot be successful.
2. Pound cocoyams thoroughly in a mortar.
3. Add hot water (the stock from the cooked cocoyam is most suitable) and continue pounding until a single homogeneous mass of the desired consistency is formed. For an elastic foofoo, do not add hot water until a solid mass has been obtained.
4. Shape into balls and serve warm in a covered dish, with okro or any suitable soup.

Source
Food and Agriculture Organization of the United Nations (1991), Post-harvest and processing technologies of African staple foods: a technical compendium, ISBN 92-5-103076-6, Rome