Cut the pork leg meat into bite-sized pieces.
Slice the onion, green onion, and garlic, and set them aside.
Prepare the marinade by mixing gochujang (Korean red chili paste), soy sauce, red pepper powder, sugar, minced garlic, sesame oil, and pepper.
Add the marinade to the pork leg meat, mix thoroughly, and let it marinate for 10 minutes.
Heat oil in a pan and sauté the green onion first to bring out its aroma.
Add the marinated meat and vegetables into the pan and stir-fry over medium heat.
When the meat is cooked through and the seasoning is well absorbed, finish and serve.