Slice the pork into bite-sized pieces.
Cut the onion, green onion, and garlic.
Prepare the sauce (gochujang, soy sauce, sugar, chili powder, minced garlic, sesame oil, etc.).
Mix the sliced pork with the sauce and marinate for 10 minutes.
Heat oil in a pan and stir-fry the green onion and garlic.
Add the pork and vegetables, stir-fry over high heat.
Add the onion and continue stir-frying together.
Finish by adding sesame oil and sprinkling sesame seeds when the pork is cooked.