Chop the onion and green onion into small pieces.
Cut the pork into bite-sized pieces.
Heat oil in a pan and stir-fry the green onion to make green onion oil.
Add the pork and stir-fry.
Add the onion and stir-fry until it becomes translucent.
Season with soy sauce, sugar, and pepper.
Add a little black bean paste or soy sauce and stir-fry.
Pour in 100ml of water and bring to a boil.
Add starch water to adjust the thickness.
Pour over rice to serve.