Wash the sweet potatoes thoroughly and peel them.
Cut the sweet potatoes into small pieces and steam them.
Mash the cooked sweet potatoes smoothly in a bowl.
Melt the chocolate using a double boiler.
Mix the mashed sweet potatoes and melted chocolate well.
Shape the mixture into bar forms and wrap them in plastic wrap.
Chill in the refrigerator for about 30 minutes until firm.
Cut into appropriate sizes and arrange on a plate.