Sweet potato powder is starch extracted from sweet potato. White powder is raw potato starch. When heated with water, it will condense into a transparent viscous state, which is actually what we usually call thickening. Before frying the meat, add a little bit of this powder and water to the lean meat you cut and mix well. You can usually scratch it with your hand. Then put it in the pot while frying, remember not to pour the sauce in. Just like the general method of frying meat. It seems that this is not added to the process of cook the meat, but it will thicken the soup. It depends on whether you need to make thick soup or thin soup.