How to Make It
Bring a large saucepan of water to a boil. In a small bowl, mix 1 tablespoon of the soy sauce with the brandy, hoisin sauce and cornstarch. Blend the mixture into the ground pork.
In a small bowl, whisk the sesame paste with the vinegar and the remaining 2 tablespoons of soy sauce until smooth. In a small saucepan, heat the chili and sesame oils. Add the garlic and cook over high heat for 30 seconds. Add the sesame paste mixture and simmer for 1 minute. Add the stock and simmer over low heat, stirring occasionally, until reduced slightly, about 3 minutes.
In a small skillet, heat the vegetable oil. Add the seasoned ground pork and cook over moderately high heat, breaking up the meat with a spatula, until cooked through, about 3 minutes. Cover the skillet and remove from the heat.
Add the bok choy to the boiling water and cook until bright green, about 10 seconds. Using a slotted spoon, transfer the bok choy to 4 small bowls. Cook the noodles in the boiling water until al dente, about 3 minutes. Drain well and transfer to the bowls. Pour the sauce over the noodles and spoon the ground pork on top. Garnish with the pickled mustard greens and scallions and serve.