Soak lap cheong in hot water for 10-15 minutes then peel off plastic casing and slice lap cheong diagonally. Remove prawn shells and veins, then soak in ice water for 10-15 minutes before frying in order to get crunchier prawns.
Heat a wok over high heat, then add 1 tbsp of oil into wok. Fry lap cheong for 1-2 minutes to release its flavour. Remove from wok and set aside. Fry prawns till no longer grey. Remove and set aside.
Add 3 tbsp of pork lard oil and 3 tbsp of pork lard (optional), then add chopped garlic and fry till brown and fragrant. If your wok is quite small, you can fry the kway teow in 2 batches so that there will be more wok hei.
Add beaten eggs into wok and scramble.
Add kway teow and dark soy sauce. Stir fry until well-combined.
Add beansprouts and chye sim, and stir fry for 1-2 minutes.
Add lap cheong, fishcake, prawns, spring onion/chives and cockles (optional) combine well.
Finally, add light soy sauce and sweet sauce and fry until the sauce chars and caramelizes. You need to char the kway teow and sauce in order to get more wok hei. If you prefer the char kway teow to be slightly wetter, add some hot water towards the end. Serve with sambal chilli if preferred.