Combine all of the sauce ingredients in a small saucepan and heat over medium-high for 1–2 minutes, just until the flavors come together. Cook longer if you prefer a thicker, more concentrated sauce. Remove from the heat, stir in the ground peppercorns, and set aside.
In a bowl, toss the pork with all of the marinade ingredients and let it rest for at least 10 minutes.
Heat a wok or skillet over medium-high heat. Stir-fry the Yacai for about 30 seconds, then add the marinated pork. Season with the light soy sauce and Shaoxing wine.
Cook until the pork is browned and cooked through, then transfer to a plate.
Cook the noodles according to the package directions, then rinse under cold water to stop the cooking.
Spoon a few tablespoons of the warm sauce into the bottom of each serving bowl.
Add the noodles, top with the pork mixture, drizzle with extra chili oil, and sprinkle with green onions.