Soak the rice noodles in some room temperature water. Set aside while you work on the filling.
Place the grated carrot and cabbage in a large sturdy sieve over the sink. Sprinkle over the salt then use your hands to massage it into the vegetables. Begin to squeeze the excess moisture from the vegetables in intervals. I like to work on them for about 10 minutes, on and off. They should have the excess liquid drained from them, look a little shrivelled and hold together in a ball. Removing excess liquid makes it much easier to form spring rolls and stops the liquid from making the pastry soggy, so this step is important.
Heat a large skillet or pan over a medium heat. Add the oil and heat until shimmering.
Add the ginger, spring onions and shiitake to the pan. Cook for 3-5 minutes or until soft and fragrant. Add a tiny splash of water if you need it.
Add the drained vegetables to the pan and stir to combine.
Use scissors to chop the vermicelli into short strands. They might feel a little tough and solid – this is perfect. We don’t want them to be overcooked. Add them to the pan and stir to combine.
Pour over the oyster sauce and stir until the mixture is evenly coated. Add the pepper, then taste and adjust for sauce and seasoning.
Remove from the heat and allow to cool before using. You can also make this as a stir fry noodle dish (see body of post) and to make rice paper rolls (see body of post).
Leftovers keep well in the fridge for 3-4 days.