Cut the pork neck into bite-sized pieces.
Wash the soybean sprouts thoroughly and set aside.
Slice the onion, green onion, and carrot into thin strips, and chop the Cheongyang chili peppers.
In a bowl, make the marinade with soy sauce, sugar, chili powder, minced garlic, sesame oil, and black pepper.
Add the marinade to the sliced pork neck, mix well, and let it marinate for 10 minutes.
Heat cooking oil in a pan over medium heat and stir-fry the pork.
When the pork is half cooked, add the soybean sprouts and vegetables, and stir-fry together.
Stir-fry until the soybean sprouts are softened, then transfer to a plate and serve.