How to Make It
Make the Black Pepper-Scallion Sauce Combine all the ingredients in a blender and blend quickly until combined but not totally smooth. Stir well before using.
Make the Dumplings Place the cabbage in a large bowl with the salt. Toss well and set aside for at least 10 minutes. In a large bowl, combine the ground pork, garlic chives, soy sauce, ginger, and sesame oil and use your hands to mix all the ingredients thoroughly together. Set aside.
Take the cabbage in your hands and squeeze as hard as you can. You will be amazed by the amount of water that comes out. Squeeze out as much water as you can and add the cabbage to the pork mixture. Mix well with your hands until the filling is well combined.
Fill a small bowl with warm water. Lay a dumpling wrapper on a clean work surface and scoop about 1 tablespoon of the filling into the center of the wrapper. Dip your finger in the water and paint all around the edge of the wrapper to moisten. Fold the wrapper over in half to look like a half-moon. (This always reminds me of making a taco shell.) Pinch just the top of the wrapper together, leaving the sides exposed and open. Start pleating the left side of the dumpling: hold the dumpling on the top, fold a pleat on one side of the wrapper about halfway down the arc toward the center of the dumpling and press it into the facing side of the wrapper. Repeat the pleating almost to the bottom of the arc so that you have two pleats on the left side of the dumpling. Repeat the pleating process on the right side of the dumpling, again pleating toward the center. When the dumpling is completely pleated, you should be able to sit the dumpling on its bottom and it will look like a little love seat. The smooth side of the dumpling will be the seat and the pleated side will be the back of the couch. Continue with the rest of the dumpling wrappers and filling until the filling has been used up.
You need a large, heavy, flat-bottomed skillet with a lid or a nonstick skillet with a lid. Heat the skillet over medium-high heat and add 2 tablespoons of the vegetable oil. When the oil starts to shimmer, carefully add as many dumplings as will comfortably fit in the skillet and turn the heat down to medium. Cook without moving the pan until the dumpling bottoms are golden brown, about 3 minutes. Check by lifting them up with your fingers and peeking underneath. Add about 2 tablespoons water to the bottom of the pan and immediately cover with the lid. The pan will sizzle and steam up immediately, so don’t be startled. Shake the pan from time to time to keep the dumplings from sticking. Let the dumplings steam for 2 minutes, at which point most of the water will have evaporated. Add another 2 tablespoons water to the pan, cover again, and steam again. Wait till the water has mostly evaporated again and repeat one last time with a final 2 tablespoons water. Turn off the heat, keep covered, and rest for 1 minute. Uncover and turn the heat back to medium-high to crisp up the bottoms. Remove from the pan. Continue in the same manner to cook the remaining dumplings, adding 1 tablespoon of oil to the pan at a time as needed. Serve immediately with the Black Pepper–Scallion Sauce.