Heat 1 teaspoon of vegetable oil in a frying pan over medium heat.
Add in the chopped mustard greens and saute for 2-3 minutes, until heated through.
Transfer to a bowl and set aside.
In the same pan, over high heat, add in the ground pork.
Cook for 2-3 minutes, breaking up the meat into smaller pieces and add in minced garlic.
Continue to cook and brown the pork.
Once the garlic is aromatic, add in the light soy sauce, dark soy sauce, sugar, Shaoxing wine, Chinese five-spice powder, and ground Sichuan peppercorn, and stir until the pork is fully cooked. Taste and adjust the seasonings.
Remove from heat and transfer to a bowl. Set aside.
Make the sesame sauce:
In a bowl, combine sesame paste with hot water. You may need to add in the hot water 1 tablespoon at a time, and continue stirring to loosen the sesame paste.
Stir in sugar, soy sauce, black vinegar, garlic, Chinese five spice powder, ground Sichuan peppercorn, and chili oil.
Taste and adjust the seasonings to your preference.
Assemble:
Add a portion of sauce to a serving bowl.
Place cooked noodles into the bowl.
Add your choice of toppings to the noodles, and mix thoroughly before enjoying.