Chef's Note: This is a traditional dish made from cooked Okinawan sweet potato. It was made from the leftover potatoes that were not consumed during the meal.
In a medium sized bowl, place the mashed cooked sweet potato. Add in the mochiko and mix well until a “play dough” like product is formed.
Brush the surface of each leaf with a little salad oil and place ¼ of the mixture in the center of each leaf.
Pull both ends of the leaf upwards to meet at the same point, fold the ends of the leaf inwards forming a cone shape and tie with the butchers twine or wrap with foil.
Steam for 30 minutes and set aside to cool and enjoy as a dessert for a Japanese New Year celebration.