¼ cup rice wine vinegar
2 tablespoons soy sauce
½ cup gochujang (Korean hot pepper paste)
3 tablespoons minced garlic
3 tablespoons minced fresh ginger root
2 tablespoons red pepper flakes
½ teaspoon black pepper
3 tablespoons white sugar
3 green onions, cut into 2 inch pieces
½ yellow onion, cut into 1/4-inch thick rings
1 (1kg) pork loin, cut into 1/4 inch slices
Rapeseed oil for frying
Stir together the vinegar, soy sauce, hot pepper paste, garlic, ginger, red pepper flakes, black pepper, sugar, green onions, and yellow onion in a large bowl. Mix in the pork slices, mixing well until completely coated. Place into a resealable plastic bag, squeeze out any excess air, seal, and marinate in the refrigerator at least 3 hours.
Heat the oil in a large pan over medium-high heat. Add the pork slices in batches, and cook until no longer pink in the center, and lightly browned on the outside, about 5 minutes per batch.