This braise is straight from the street stalls and rice shops of Bangkok’s Chinatown. It can be served wet – that is, as a soup – or dry, as here, when it is more like a dish of braised vegetables. The Westerner in me wants to suggest you use stock for this, but in fact plain water is used on the street. Almost any type of Chinese green-leafed vegetable can be thrown into the mix, along with the roast duck (or pork) from a Chinatown barbeque shop. Yellow bean sauce can usually be found just down the road from the barbeque shop, in any Asian grocer. It’s almost like unstrained soy sauce or miso – look for one containing whole soy beans. I find this dish tastes much better the next day, and it will keep well for several days – just bring it to the boil every few days to keep it sweet.