Wash the bean sprouts thoroughly and drain the water.
Prepare thinly sliced pork belly.
Chop onion and green onion.
In a pot, place the bean sprouts on the bottom, then add the pork belly, onion, and green onion on top.
Mix gochujang (Korean chili paste), soy sauce, minced garlic, red pepper powder, sugar, and sesame oil to make the sauce.
Evenly pour the sauce over the ingredients.
Cover and steam over medium heat for 7–10 minutes.
Transfer the finished dish to a plate.