In a large bowl, combine the ground pork, chopped onion, minced garlic, grated ginger, soy sauce, gochujang, sesame oil, breadcrumbs, beaten egg, green onions, and sesame seeds. Mix well until all ingredients are evenly incorporated—season with salt and pepper to taste.
Using your hands, shape the mixture into small patties, about the size of a golf ball, and flatten them slightly.
Heat a generous amount of vegetable oil in a large skillet over medium heat. Once hot, add the rissoles in batches, ensuring not to overcrowd the pan. Fry each side for about 3-4 minutes or until golden brown and cooked through.
Transfer the cooked rissoles to a plate lined with paper towels to drain any excess oil. Serve hot with a side of rice, kimchi, or a fresh salad. You can also garnish with additional sesame seeds and sliced green onions for a bit of extra flair.