There should be a reasonable formula for making potato, which requires not only glutinous rice flour but also corn starch. Many people don't know how to add corn starch, but don't underestimate this corn starch, which has a great effect. Adding corn starch can not only reduce the viscosity of the finished product, but also improve the taste. If potatoes are only made of glutinous rice, the taste will be sticky and plastic surgery will be difficult. Adding corn starch will make the finished product more delicate. Secondly, butter is also needed to make yam. Butter can make yam taste more fragrant, with a little milk flavor, and also prevent yam from drying out. Therefore, butter is necessary to keep yam soft and waxy.