Chop the cabbage into large pieces.
Trim off and discard the ends of the enoki mushrooms and cut into bite-sized pieces.
Place cabbage and enoki mushrooms in a skillet. Mix the sauce A (soy sauce, vinegar, sugar, sesame oil, sesame seeds, and garlic) and set aside.
Lay the pork slices on top, sprinkle with salt and pepper, and drizzle with 3 tbsp. water.
Cover and cook over medium heat. Once it starts to simmer, reduce to medium-low and steam for 8–10 minutes.
When the pork is fully cooked, turn off the heat and gently separate the slices. Pour the mixed A sauce evenly over the dish.
Garnish with chopped green onion, if desired, and serve warm.