Place the noodles in a large bowl and cover with boiling water. Let soak until softened, 10 to 15 minutes. Drain
and toss with 1/2 teaspoon toasted sesame oil to prevent sticking.
In a small saucepan
, heat the beef stock to a simmer
and then keep warm on low heat.
In a small frying pan
set over medium heat, dry-toast the peppercorns
until fragrant. Remove from the heat and crush in a mortar and pestle
, place in a plastic bag and crush
with a rolling pin
or use a spice grinder
Heat a wok over high heat and add the peanut oil
. Add the garlic, ginger
, chili and 1 tablespoon of the ground peppercorns and stir-fry
a few seconds. Add the pork
and chili bean sauce and continue stir-frying. As the pork browns, add the rice wine. When the pork has browned, add the tofu
and mix gently. Season the stir-fry with soy sauce,
black rice vinegar
, the remaining 1 teaspoon sesame oil, salt and ground white pepper.
Add the hot beef stock
to the pork and tofu and bring to a boil. In a small bowl, stir together the cornstarch and 2 tablespoons water, then stir into the sauce to thicken. Stir in the scallions
and remove from the heat. Serve over the noodles and sprinkle with the remaining peppercorns.