Carefully add frozen jiaozi (dumplings) to the water. NOTE: Do not drop from a great height because boiling water will splash. Have courage, bring the dumpling near the surface of the boiling water, and let it slip gently into its warm bath.
Return to a low boil and cook for 7 minutes, until outside of jiaozi is tender, and inside is cooked through. NOTE: Dumpling wrapper will have the texture of al-dente pasta. If you like a softer texture, boil a couple minutes more.