Cut the pork butt into thin, large pieces, about 1cm thick.
Add scallion, ginger, oyster sauce, black pepper, starch, and water. Mix well until all the liquid is fully absorbed and the pork butt is evenly coated. Lastly, brush the surface with a little oil. Set aside for 10 minutes.
You can marinate the pork chop in advance; remember to marinate in an airtight container in the fridge.
Pan-frying
Heat the pan until very hot, add oil, then place the pork chop in. Fry until one side is well seared, then flip and fry the other side. This process takes around 2 minutes.
Cut the pork chops into smaller pieces and continue searing for about 10 seconds over high heat.
Simplified Black Pepper Sauce
Add some oil and fry the garlic and red onion until slightly soft and aromatic. Add stock or water, and season with ground black pepper, oyster sauce, light and dark soy sauce, sugar, and salt. Then reduce the heat and pour in the starch water.
Simmer for another minute, until the sauce thickens and the aromatics and seasonings meld.