According to official website, this is a folk custom in Hong Kong. Hong Kong soup pot refers to a pot with a fatter bottom than the top, like a big belly. Hong Kong-style soup is cooked with strong fire. Then turn to medium heat and let the soup boil in the pot.
The Hong Kong Special Administrative Region, the full name of which is People's Republic of China (PRC) Special Administrative Region, is located in the south of China, east of the Pearl River Estuary, and across the sea from Macau to the west.