Heat up a wok or pan on high heat, then pour in 2 tbsp oil. When hot, turn the heat to medium and throw in the chopped onion and red shallots.
Stir for 30 seconds or until fragrant, then turn the heat to high and add in the ground pork.
Break the pork up and stir. Mix in the sugar, salt, chicken bouillon powder, pepper and fish sauce, then cook for 3 minutes or until 80% cooked.
Add the woodear and shiitake mushrooms and scallions/spring onions in, then stir for another 2 minutes. Turn off the heat and let it cool as you work on the dough.
Stir together the tapioca, potato and arrowroot starches with the rice flour, salt, pepper and chicken bouillon powder in a large mixing bowl.Note: You can also mix them together in a large pot as you will be cooking it in there.
Pour the stock over the flour mixtures, stir until it has become liquid and add the oil in. Make sure that by the end, there is no resistance from the starch as you mix.
Transfer the mixture into a large deep pan or wok and turn the heat up to medium-high.
Stir using chopsticks until it starts to produce strands when you lift up the chopsticks, then increase the stirring speed until the liquid forms a sticky dough.
This will take about 10 minutes. When it has formed a paste, let it rest as you prepare the banana leaves.