1. The lid of the pot cannot be kept covered or opened during the whole process. Open the lid to cook the stuffing, so opening has the function of opening, and lid has the function of covering.

2. As the saying goes: "Open the pot to cook the stuffing, cover the pot to cook the skin." When the pot is open, the surface of the dumplings is in direct contact with the outside air, dissipates heat quickly, and the temperature is lower than the temperature in the pot, while the dumpling fillings are in direct contact with the outside air. Wrapped in skin, heat cannot escape easily and can maintain a higher temperature.