In a large pot, bring water to a boil and cook the noodles according to package instructions.
Cook until al dente, then drain and rinse under cold water. Give the colander a few good shakes to prevent the noodles from clumping, and then set aside.
While the noodles are cooking, prepare the sauce by combining all the ingredients in a small bowl. Whisk well.
Heat wok over high heat. When the wok is hot, swirl in 1 tbsp of oil to coat the bottom.
Add in half of the minced garlic and ginger, and stir-fry until aromatic, about 30 seconds.
Add in the shrimp, and cook until they just start to turn pink and opaque, about 2-3 minutes. Transfer the shrimp to a plate, and set aside.
Swirl in another tablespoon of oil. Add in the rest of garlic & ginger, and also the mushroom slices and the white parts of the scallion. Stir-fry for about a minute. Add in sugar snap peas, and stir-fry over high heat for another minute. Add in carrots, bell peppers and napa cabbage. Continue to stir-fry for just about 2 minutes. Add in one or two splashes of Shaoxing rice wine or dry sherry. Give everything a quick toss.
Add in the bok choy (or other greens), and give it another quick toss. Then quickly loosen the noodles by giving the colander a good shake before you fold the noodles into the wok. Scoop and toss everything together. Return the cooked shrimp to the wok. Then pour in the sauce around the edges of the wok. Add in the green parts of the scallion. Continue to fold and scoop and toss over high heat until everything is coated well with the sauce. Add in one or two splashes of water if you like it to be more saucy. When the sauce cooks down and everything is well combined, dish out and serve.