Cut pork belly and vegetables into bite-sized pieces.
Slice onion, green onion, and garlic.
Mix gochujang, red pepper powder, soy sauce, sugar, minced garlic, and sesame oil to make the seasoning sauce.
Put pork belly in a pan and stir-fry to render the fat.
Add onion, green onion, and garlic and stir-fry.
Add the seasoning sauce and fry the meat and vegetables together.
Finish by sprinkling sesame oil and sesame seeds.