Mix the sesame paste, chili paste, light soy sauce, garlic, sugar, five-spice powder, and Sichuan pepper in a bowl. Gently stir in the chili oil and hot broth, leaving some oil visible on the surface.
In a small bowl, combine the hoisin, dark soy sauce, Shaoxing wine, and five-spice powder.
Heat 1 Tbsp vegetable oil in a 12-inch skillet or wok over high heat. Add the pork and break it into small crumbles. Cook until completely opaque, add the seasoning mixture, and cook for 1 minute. The pork should reach 160°F (71°C) if checked with a thermometer. Transfer to a bowl.
Return the pan to medium heat. Add 1 tsp vegetable oil and cook the sui mi ya cai for 30 seconds. Set aside.
Bring water to a full boil in a 6- to 8-quart pot. Cook the noodles according to their package directions, adding the choy sum for the final minute. Drain when the noodles retain a slight bite and the greens are bright and crisp-tender.
Divide the sauce among four bowls. Add the noodles, pork, sui mi ya cai, and choy sum. Top with green onions and optional peanuts. Mix thoroughly and serve immediately.