In a microwave-safe bowl, cover the shiitake with water and microwave at high power for 2 minutes. Let stand until plump, about 10 minutes. Drain, rinse and pat dry. Thinly slice the mushrooms.
In a saucepan of boiling water, cook the noodles until al dente, 3 minutes; drain and rinse the noodles. In a bowl, combine the broth, soy sauce, vinegar, sesame oil, chile-garlic sauce and sugar.
In a large nonstick skillet, heat the vegetable oil. Add the ginger and shiitake and cook over high heat, stirring, for 3 minutes. Add the noodles and scallions and stir-fry until lightly browned, 5 minutes. Add the pork and sauce and cook over moderate heat, tossing until the sauce is absorbed, 3 minutes. Transfer the noodles to a platter, garnish with scallions and chiles and serve.