Clean the pork belly and soybean sprouts thoroughly and prepare them into bite-sized pieces.
Heat some cooking oil in a pan and stir-fry the pork belly.
When the pork belly is halfway cooked, add sliced onion and green onion and stir-fry together.
Add the soybean sprouts, then stir-fry with soy sauce, red pepper powder, and minced garlic.
Once all ingredients are cooked through, season with sesame oil and black pepper.
Transfer to a plate and sprinkle sesame seeds on top to finish.