In Cantonese cuisine, it is a form of tong sui, or sweet soup. The main ingredient is crushed black sesame seeds in a flour form. It is boiled with hot water. Sometimes, granulated sugar are added, though the sesame seeds are usually sweet enough by default. It can now also be easily home-made using instant packets. The soup is perhaps the thickest of all tong sui.
Other Chinese cuisine
Other Chinese cuisine often add ''tangyuan'' into black sesame soup.