Cut the pork leg into bite-sized pieces.
Slice the onion, green onion, and carrot into thin strips.
Make the seasoning sauce with gochujang, soy sauce, minced garlic, chili powder, sugar, sesame oil, and pepper.
Mix the pork and vegetables with the sauce.
Heat cooking oil in a pan and stir-fry the pork over medium heat.
Once the pork is cooked and the sauce thickens, it's ready to serve.