Iyan is made from pounding yam repeatedly with a  Pestle inside a Mortar. The yam is first peeled then washed in clean water. It is then boiled till its soft and then placed in the mortar. This Flour has already been pounded and then dehydrated for your convienience. It has a similar taste to "mashed potatoes" and is typically served with egusi stew or any other tomato based stew.
 
sometimes used in addimu to Orisha
 
Product of Nigeria