This is a light dish made from tofu
. One can have it warm on its own, or with some sugar syrup in winter, or have it cold (on its own or sugar syrup) in summer time. It can be a dessert or a snack. It's a great alternative to ice-cream in summer time (especially in the sweltering heat in Hong Kong).
In Tai Po Hui, there's a famous shop that sells Tofu fah called "Ah Paw Doufu Faah" or 阿婆豆腐花. It's been around for a long time, started of as a street stall.