Add the Sichuan peppercorns, star anise, garlic, shallots, green onion and vegetable oil to a small saucepan. Bring the mixture to a simmer over medium heat until the garlic and onion are just golden brown, careful not to overcook, about 10 minutes.
Remove the pot from heat. Stir in the crushed red pepper flakes and let the oil cool completely.
For the pork:
Heat a wok over medium-high heat, add 2 tablespoons of the vegetable oil and heat through. Add the ginger and garlic and stir for a few seconds until fragrant.
Add the ground pork and cook, using a spatula to break up the meat, until cooked through and the edges are slightly crispy, about 6 minutes.
Add the soy sauce, black vinegar and 5 spice powder to the meat and stir to combine then remove to a medium mixing bowl.
Return the pan to medium heat and add the remaining vegetable oil. Add the bok choy and sauté until tender and bright green.
For the sauce and dan dan noodles:
Bring a large pot of water to the boil; add the salt and bring back to the boil. Add the noodles and cook, stirring occasionally, until al dente, about 10 minutes. Drain and toss with 1 tablespoon of the sesame oil then set aside.
In a small bowl whisk together the remaining sesame oil, chicken stock, soy sauce, ¼ cup of the homemade crunchy chili oil, sesame paste or peanut butter, rice wine vinegar and sesame seeds stirring to combine.
For serving:
In a large serving bowl add the sauce and add the cooked noodles. Top with the pork mixture, bok choy, green onions and peanuts. Toss to combine and serve with additional crunchy chili oil as desired.