Cook the noodles until al dente, then set aside.
Sauce #1. In a bowl, mix ¼ cup chicken broth, 1 tablespoon hoisin sauce, 2 tablespoons mirin, and 2 tablespoons low-sodium soy sauce. Set aside.Sauce #2. In a bowl, mix in 1 tablespoon hoisin sauce, 1 tablespoon sesame oil, 1 tablespoon dry sherry, and 2 teaspoons chili garlic sauce. Set aside. Preheat a wok over medium-high heat without oil. Cook ground pork undisturbed until browned, about 3 minutes. Break it up and toss until no pink remains, about 1 minute. Stir in sauce #1 until coated, then transfer to a plate and set aside.
In the same wok, heat 2 tablespoons vegetable oil over medium-high heat. Add chopped scallion (white part), garlic, ginger, and Sichuan peppercorn. Cook, tossing often, for about 30 seconds or until fragrant.
Add the browned pork back to the wok. Keep stirring for about 30 seconds.
Add the noodles to the wok and give a quick stir. Then stir in sauce #2. Cook, tossing often, for 45 seconds to 1 minute until the noodles are coated. Adjust seasoning if needed.
Remove from the heat. Serve with the remaining scallions (green part).