Cut the pork into bite-sized pieces.
Prepare the vegetables such as onion and green onion.
Mix the sauce ingredients (soy sauce, sugar, garlic, sesame oil, red pepper flakes, black pepper, etc.).
Marinate the pork and vegetables in the sauce for 20 minutes.
Heat oil in a pan and stir-fry the marinated pork and vegetables.
Stir-fry over medium heat until fully cooked.