Cut the pork hind leg into bite-sized pieces.
Finely chop onion, green onion, and garlic.
Make a marinade with gochujang (Korean chili paste), chili powder, soy sauce, minced garlic, sugar, sesame oil, and pepper.
Add the marinade to the pork and let it marinate for 20 minutes.
Heat cooking oil in a pan and stir-fry the onion and green onion.
Add the marinated pork and stir-fry over high heat.
When the meat is fully cooked, drizzle with sesame oil to finish.