In a small saucepan set over medium heat, combine the soy sauce, brown sugar, chili garlic sauce, rice wine vinegar, sesame oil, black pepper, ginger, garlic, and green onions. Bring to a simmer. Meanwhile, mix the cornstarch and water until smooth. Whisk in the cornstarch slurry and bring back to a simmer. When pork is finished add 1 portion (1/3 of total cooked pork) to a medium bowl and add the Korean BBQ, a little at a time, to taste.