Dice the pork, onion, and potato into cubes.
Heat oil in a pan and stir-fry the pork.
Add onion and potato, and stir-fry together.
Once the vegetables are cooked, add the black bean paste and stir-fry.
Add water, potatoes, and peas, and bring to a boil.
Season with cooking wine, sugar, and soy sauce.
Mix starch with water and add to adjust the thickness.