Second, put more oil properly.
Third, the fire should be big and fierce, the oil temperature should be high, and the fire should be fried quickly. Don't overheat, just boil it, don't cover it.
Fourth, after frying a few times, order some cooking wine, which can keep the green color longer.
5. thicken with water starch when cooking quickly, so that it will not change color for a long time after cooking.