Cut onion, pork, potato, and zucchini into bite-sized pieces.
Add oil to a pan and stir-fry the pork.
Add onion, potato, and zucchini, and stir-fry together.
Add black bean paste (chunjang), mix well, and stir-fry.
Add soy sauce, sugar, and water, and bring to a boil.
Add starch water to adjust the thickness.
Pour the sauce over the boiled noodles.