1. Remove 4 medium mushrooms from the soaking water squeezing out excess water from the shiitake mushrooms (do not throw away the soaking water).
2. Soak glass noodles in the mushroom water, adding more water as needed to submerge the noodles. soak for 7-10 minutes until softened.
3. While the noodles soak, remove the stems from the shiitake mushrooms and finely chop the caps. finely dice 0.25 oz black fungusmushrooms. [if you find any hard parts (that's the root end) cut around them and discard]. place the mushrooms in a large bowl together with 2 cups finely julienned taro, 1&3/4 cup finely julienned cabbage and 1 cup julienned carrots.
4. Once noodles are done, drain the water but do not throw it away. don't toss the noodles so that the strands remain in alignment for easy cutting. use scissors to cut the noodles into 2-inch pieces.
5. In a wok or a large non-stick saute pan, add the 2 tbsp oil, 4 cloves of minced garlic, 1 tsp white or black pepper and saute for about 2 minutes over medium heat or until the garlic starts to turn golden.
6. Turn the heat up to medium high and add the mushrooms, taro, cabbage, carrot. add 1 tbsp of the soy sauce; cook for 3-4 minutes until the taro is done. you can tell that the taro is getting close to done when some of the pieces start to break; you can then taste to see if they're cooked through.
7. Add the glass noodles, 8-10 cilantro stems, the remaining 1 tbsp soy sauce, 1 tbsp sugar, and about 1/4 cup of the mushroom soaking water. toss until the noodles are fully cooked, adding a splash more of the mushroom water if needed.
8. Toss in the 2 green onions and remove from heat. taste the filling and add the salt if it needs it.
9. Transfer the filling into a large shallow bowl and spread it out so it can cool quickly.
10. For the spring roll wrapper glue, you can use a beaten egg, or for a vegan glue, mix the all-purpose flour with an equal amount of water so you have a thick but spreadable paste.
11. To wrap, follow the instructions in the video. use a little more than 1/4 cup of filling per roll if using a large (8-inch) wrapper. at this point you can freeze the spring rolls and fry them directly from frozen.
12. Heat 2-3 inches of oil in a wok. add the spring rolls, a few at a time so as to not crowd the pot. fry on medium heat for about 5-6 minutes until golden brown and crispy. if they are frozen they may take 7-8 minutes.
13. Thai spring rolls are ready to serve with sweet chilli sauce.