Step 1

In a medium bowl, whisk together the 2 teaspoons soy sauce, the sherry, sugar and cornstarch. Add the pork and toss to coat; set aside. In a small bowl, combine the remaining ¼ cup soy sauce, oyster sauce, vinegar and ½ teaspoon white pepper; set aside.

Step 2

In a large pot, bring 4 quarts water to a boil. Add the noodles and cook, stirring occasionally, until just shy of tender. Drain in a colander and rinse under cold water, tossing well, until cool to the touch. Drain again, shaking the colander to remove as much water as possible. Drizzle with the sesame oil and toss to coat; set aside.

Step 3

In a 12-inch skillet over medium-high, heat the neutral oil until shimmering. Add the pork in an even layer and cook, stirring occasionally, until lightly browned, 1 to 2 minutes. Using a slotted spoon, transfer the pork to a plate.

Step 4

To the now-empty skillet, add the bok choy; cook, stirring often, until the leaves are wilted and the stems are translucent, about 2 minutes. Add the noodles and soy mixture. Cook, stirring often, until the noodles have absorbed most of the liquid, 3 to 4 minutes. Add the pork and any accumulated juices. Cook, tossing, until the noodles are dry, 1 to 2 minutes. Off heat, taste and season with white pepper.