Sweet Black Sesame Soup

Soak the glutinous rice overnight. Toast the black sesame on the stove for about 2 minutes until you hear popping sounds. Grind the soaked rice, toasted black sesame, and red dates together until smooth (do not add the rock sugar yet). Sift out any residue from the ground mixture, and pour more water through the residue to extract maximum flavor and substance. Cook the sieved mixture for about 5 minutes, adding the rock sugar, until it starts bubbling.