After the water is boiled, put the fungus in and cook for about two or three minutes. If you are afraid of undercooking, you can cook it for a while. You can also soak it in warm water first, then blanch it with boiling water and eat it cold, or eat it after frying. Rinse with running water several times after soaking, which can reduce pesticide residues. If the black fungus is cooked for too short a time, it may carry bacteria on the surface, causing indigestion and affecting health.