Place pork on a flat surface and roll tightly. Secure the pork with kitchen twine. Heat a pan and brown the pork I all sides. Mix the soy sauce, mirin, and water using a wire whisk. Pour mixture into the pan and add in green onion, ginger, garlic, and star anise. Cook for one and half hours. Let cool and remove the kitchen twine and store it until needed.
Notes
This recipe was adapted from Seonkyong Longest Blog.