Iyan and Efo Riro. Iyan is Yoruba for 'Pounded Yam,' and Pounded Yam is exactly what it is,'Pounded Yam.' Pounded Yam is eaten with various soups and stews, including Efo Riro. Efo Riro is a vegetable soup originating from Southwest Nigeria (Yoruba people) and is made of spinach, palm oil, peppers, and onions. Efo Riro is cooked with different meats and fish.