Cut the pork ham into bite-sized pieces.
Prepare and slice the onion, green onion, and garlic.
Make a seasoning sauce with gochujang (Korean red chili paste), gochugaru (red chili flakes), soy sauce, minced garlic, sesame oil, and black pepper.
Coat the pork evenly with the seasoning sauce and marinate for 10 minutes.
Heat some cooking oil in a pan, then add the pork and vegetables. Stir-fry over medium heat.
Stir-fry until the pork is fully cooked through.
Sprinkle sesame seeds to taste and serve.