Heat the pan first, and don't put oil in it. Dip chopsticks in the pot with a drop of water to see the temperature. If the water drops swirl in the pot, it proves that the temperature of the pot is ok. Then oil the hairtail. Remember to turn down the fire a little after putting hairtail, or the pot will burn easily if it is too hot. After frying, you can directly wash the pot with clean water, and the water temperature is very high.