The flat, sticky rice noodles of the famous cao lau are said to be made only with water from a Cham well at a village in Hoi An city. Lye solution from a nearby Cham island is reportedly used, too. If such are the secret to its distinct taste, then there are other ingredients that make this dish unmistakably Vietnamese. Bean sprouts are part of the mixture, as well as green cabbage, coconut extract and water mint.
Of course, it is topped with roast pork and is sometimes served with chilli or shrimp paste. As with most local cuisine, the best tasting, authentic cao lau comes in steaming bowls sold in street stalls. Variations of the dish can be found throughout the country, although these are said to inferior in taste, especially without the so-called secret ingredient of Cham well water.