Cut the pork into bite-sized pieces.
Slice the onion, green onion, and garlic.
Mix gochujang (red chili paste), soy sauce, sugar, red chili powder, garlic, and sesame oil to make the sauce.
Add the sauce to the pork and mix well. Let it marinate for 10 minutes.
Heat some cooking oil in a pan and stir-fry the pork.
Add the onion and green onion, and stir-fry together.
Once the meat is cooked, drizzle a little sesame oil on top.