Dao Suan

Do you know what are the basic ingredients that go into a delectable serving of dao suan? Let's see: there's mung beans (AKA green beans), rock sugar, potato flour with water (as a thickener)... Is that all? Don't forget the yew char kway, okay! It's Uncle Wong's favorite, which was why his co-sampler Madam Foo let him have all of it. Aww...