Step1:Add the glutinous rice flour with the mashed purple sweet potato and ice sugar water until the dough surface is smooth.
Step2:Knead into a circle with a diameter of 1.5cm.
Step3:Boil the boiling water in a big fire and change it to a small one. Remove it.
Cooking tips:The water from Tangyuan will be blue. It's the natural color of purple potato. There are skills in making delicious dishes.