Put chai ko is a traditional snack originating from Hong Kong. It consists of brown sugar, red beans, rice flour, and wheat starch or cornstarch. The red beans are cooked and mixed with flour, sugar, and water in a pan. The thick batter is then placed into a greased tin mold and steamed until done.

The snack is left to cool down and it's then taken out of the mold and served. This snack can be bought from street vendors, and in the past they would traditionally steam it in earthenware bowls, but nowadays it's mostly sold in plastic bags or aluminum cups.