Place the pork in the freezer for 30 minutes before you begin slicing it – you’ll get thinner pieces.
Soak mushrooms in about 2 cups hot water and set aside. Bring a large pot of salted water to a boil. Add noodles and bring to a boil. As soon as the water boils, add 1 cup cold water and return to a boil. As soon as the water boils again, add a third cup cold water. When it returns to a boil, drain and rinse with cold water. Set aside in a large serving bowl.
Drain mushrooms, slice thinly, and set aside. In a large wok or sauta© pan, heat 2 tablespoons oil to high. Add half of scallions to pan and saute until bright green and wilted, about one minute. Add pork and soy sauce, and saute, stirring often, about 2 minutes. Add carrots and salt, and cook, stirring often, about 2 minutes. Add bean sprouts and cook, stirring often, about 1 minute. Add mushrooms, and cook, stirring often, about 1 minute. Add cabbage, and cook, stirring often, about 1 minute, or until wilted. Remove pan from heat.
In a separate wok or saute pan, heat remaining 2 tablespoons of oil to high. Add garlic chives and remaining scallions, and saute until wilted. Season with salt and pepper to taste. Add collected liquid from first pan of cabbage and pork. Add cooked noodles and stir well; saute 2 minutes, or until heated through and well coated. Add cabbage and pork mixture, and toss well to coat noodles.