Soak cellophane noodles in water for 15-30 minutes until they become soft. You can speed it up by using warm water. Discard water, rinse noodles and set aside.
Soak dried wood-ear mushroom and shiitake mushroom in hot water for 5-7 minutes or until they are fully rehydrated. Remove stems and slice into thin strips. We need about ¾ cup sliced wood-ear mushroom and 2 tablespoons sliced shiitake mushroom.
Peel and julienne carrot. If you have time, pick and discard the yellow beans from beansprouts since we only need the white stems and it will make the final dish prettier, but it is completely optional.
Whisk all ingredients to make the lime fish sauce dressing to combine and set aside.
Place a pan/skillet over medium high heat. When it's hot, add oil. Add 1 tablespoon of minced shallots and cook for a minute until fragrant. Add crab meat, stir and add 1-1½ teaspoon of fish sauce. Cook until crab meat is heated through and set aside.
Add a generous amount of oil to coat the pan, then sauté the remaining minced shallots until fragrant. Add shiitake mushroom, stir and cook for 30 seconds. Add wood-ear mushroom, carrot and 1 tablespoon of stock or water, and continue to stir and cook for about 2 minutes.
Slightly reduce the heat and add noodles together with ¼ cup (60ml) of stock. Mix and cook for a minute. Add 1 tablespoon of fish sauce and mix. Gradually add stock by a couple of tablespoons while constantly mixing to cook the noodles for another minute or until it is almost soft to your liking. If the noodles start clumping while stir-frying, reduce the heat.
Add beansprout stems and quickly mix everything together for 30-60 seconds. Add crabmeat and scallions. Continue to mix and stir for about 30 seconds until noodles are soft and everything is cooked.
Once everything is cooked, remove the pan from the heat. Transfer to serving plates right away and sprinkle a lot of black pepper on top. Serve hot with the lime fish sauce dressing.