Steps

1. Trim the ends of the green onion. Cut about half of the green onion lengthwise and remove the core. Finely chop the part with the core removed and the other half of the green onion to make shredded green onion (shiro negi).
   🕒 01:07
2. Soak the shredded green onion in water to remove its sharpness and make it crisp.
   🕒 01:38
3. Finely chop the core of the remaining green onion and the rest of the green onion not used for shredding.
   🕒 01:55
4. Place 300g ground pork in a bowl. Add a pinch of salt, 1 tsp soy sauce, 1 clove equivalent of grated ginger, and 5 tbsp cooking sake (rice wine) from [A]. Mix well by hand. (This is the secret!) Adding plenty of cooking sake makes the meat tender and juicy, and eliminates any gamey odor.
   🕒 02:18
5. Add the finely chopped green onion and 1 tbsp potato starch to the bowl and mix by kneading. Once the mixture is well combined and becomes stringy, divide it into approximately 10-12 portions.
   🕒 03:51
6. Heat 1 tbsp vegetable oil in a frying pan. Before turning on the heat, shape the divided meat mixture by hand into dumplings and arrange them in the pan.
   🕒 04:47
7. Turn the heat to medium-high and cook the dumplings until both sides are nicely browned. If any sides are still raw, roll them around to brown the entire surface.
   🕒 05:34
8. Reduce the heat to low, add 1 tbsp cooking sake (rice wine) for steaming, cover with a lid, and steam-fry.
   🕒 06:47
9. In a separate bowl, combine 3 tbsp black vinegar, 2 tbsp sugar, 1 tbsp cooking sake (rice wine), 2 tbsp soy sauce, and 1 tsp potato starch from [B]. Mix well to create the black vinegar sauce.
   🕒 07:05
10. Wipe off any excess oil and impurities from the steamed dumplings with a paper towel.
    🕒 07:57
11. Pour the prepared black vinegar sauce into the frying pan. Bring to a simmer and coat the dumplings evenly with the sauce. Simmer until the sauce thickens.
    🕒 08:02
12. Once the sauce has thickened, transfer the dumplings to a serving dish and top with the soaked shredded green onion.
    🕒 08:27
13. Sprinkle with coarse black pepper to taste, if desired.
    🕒 08:39