- In a bowl, mix together pork, soy sauce and ginger. In another bowl, combine sugar, cornstarch, sesame oil, oyster sauce, cooking wine, water, a pinch of salt and a dash of pepper. Mix well.
- In a pan, heat up oil over medium heat. Put in pork and cook, breaking the pork into pieces using your spatula. Once they are cooked, add shrimp and stir fry until pink. Pour in the bowl of sauce mixture and stir until well combined. Transfer to a bowl and mix in spring onions. Allow to cool then, refrigerate for at least 2 hrs to marinade.
- Spread out yam pieces on a plate and steam over boiling water until softened, around 20 mins. Remove from steamer and mash them immediately into paste. Set aside.
- Place wheat starch into a bowl and carefully stir in boiling water to form a rough dough. When the dough mixture has cooled down slightly to a very warm temperature, add mashed yam and mix well. Place in lard, baking soda, salt and sugar. Fold and knead the dough until smooth, removing any yam lumps at the end. Roll the dough into a ball and cut into 4 equal portions. Roll each portion into a log and cut into 6 equal pieces. Using your palm or rolling pin, flatten each dough and roll into a dumpling wrap. Fill each dumpling wrap with the marinated filling and fold the wrap into half-moon shaped dumpling.
- In a wok, heat up enough oil for deep frying over high heat. To test if the oil is sufficiently hot, drop a piece of yam lump into the oil. If it stays at the bottom of the wok for a sec before floating to the top, the oil is ready. Gently put in pieces of yam dumplings into the wok of hot oil and fry until browned. The dumplings should also be covered with crispy nettings. Remove and drain off excess oil by placing the fried dumplings on paper towels. Serve immediately.