Prepare the Cabbage: Separate the white and green parts of the napa cabbage leaves. Finely dice the white stems and chop the leaves separately.

Create the Garlic Paste: Use a mortar and pestle to pound the white peppercorns, garlic, and ginger together into a fine paste.

Sauté the Aromatics: In a large skillet over medium heat, add a splash of oil and the garlic paste; sauté until aromatic, about 2 minutes.

Cook the Napa Cabbage: Add the diced napa cabbage stems and 1/4 tsp salt, cooking until softened, about 4-5 minutes. Then, add the cabbage leaves and cook for another 2-3 minutes until wilted. Remove from heat and let cool.

Prepare the Filling: In a bowl, combine ground pork, remaining salt, soy sauce, dashi powder (if using), toasted sesame oil, tapioca starch, and sugar; knead the mixture for about 5 minutes until well mixed.

Mix in the Vegetables: Add the cooled cabbage and garlic chives into the pork mixture. Combine gently, and taste the filling for seasoning. Adjust if necessary.

Fill the Wrappers: Scoop about a tablespoon of the filling into each dumpling wrapper, wet the edges with water, and seal tightly. You can freeze them at this stage if you're not cooking immediately.

Make the Dipping Sauce: In a small bowl, mix rice vinegar, soy sauce, sugar (if desired), and chili oil (if using).

Cook the Dumplings: In a non-stick skillet, add oil over medium heat and arrange the dumplings in a single layer. Fry for 3-5 minutes until they’re well-browned on the bottom.

Steam the Dumplings: Carefully add 1/4 cup water to the pan, cover, and steam for 3-5 minutes until fully cooked, aiming for an internal temperature of 160°F (70°C).

Serve: Serve the dumplings crispy side up on a plate with the dipping sauce on the side.