Cut the pork into bite-sized pieces.
Slice onion, green onion, and carrot into thin strips.
In a bowl, mix gochujang, chili powder, soy sauce, sugar, minced garlic, sesame oil, and pepper to make the seasoning sauce.
Add the seasoning sauce to the pork, mix well, and marinate for 10 minutes.
Heat cooking oil in a pan and stir-fry the pork.
When the pork is halfway cooked, add the sliced vegetables and stir-fry together.
Once the vegetables are tender and the pork is cooked through, transfer to a plate.