It is made from flat rice noodles (河粉 hé fěn in Mandarin Chinese) of approximately 1 cm or (in the north of Malaysia) about 0.5 cm in width, stir-fried over very high heat with light and dark soy sauce, chilli, a small quantity of belachan, whole prawns, deshelled cockles, bean sprouts and chopped Chinese chives.
The dish may commonly be stir-fried with egg, slices of Chinese sausage and fishcake, and less commonly with other ingredients. Char kway teow is traditionally stir-fried in pork fat, with crisp croutons of pork lard, and commonly served on a piece of banana leaf on a plate.
As the dish has become increasingly popular, many cooks have come up with their own interpretations of the same basic main ingredient of ricecake strips/flat rice noodles fried with anything from eggs (chicken or duck), onions, garlic, prawns, cockles, Chinese sausage, etc.
Of all the notable versions, the Penang style of char kway teow is the most famous. Its popularity leads many char koay teow sellers outside Penang to call their products "Penang char koay teow" in order to attract customers.
In the past it was usual to stir-fry char kway teow in pork fat without eggs (which were, however, available on request). More recently, ordinary cooking oil is commonly used for health or religious reasons, and eggs have become a standard ingredient in the dish.
The char kway teow in Kampar, Perak, Malaysia, is served with cockles but with no prawns (although prawns may be available on request). According to old Kampar char kway teow sellers, this is because Kampar was not near any source of fresh prawns. Kampar char kway teow is also slightly sour.
In other parts of Malaysia, such as Miri in East Malaysia, additional ingredients may include beef, onions, sweet soya sauce, etc. Versions of char koay teow prepared by Muslims in Malaysia will exclude pork fat and may include extra soy sauces and spices and the use of broader-width flat rice noodles. There are also vegetarian varieties that may or may not include eggs.
There are also "gourmet" versions of char kway teow, commonly found in Ipoh and Penang, where the dish may be prepared with more seafood, with crab meat and with duck eggs.
Source: http://en.wikipedia.org/wiki/Char_kway_teow
