GYOZA

Steps:

• Grind the pork belly using a meat grinder if you have one, or chop well with a chef's knife (do not use a food processor, which will turn the meat into a paste). Combine in a large bowl with the ground pork and refrigerate.
• To make the sprouts, combine the mustard powder, water, soy sauce, vinegar, and sugar in a bowl, mix well, and set aside.
• In a pot over high heat, bring 4 cups water and the salt to a boil. Add the bean sprouts. Remove from the heat when the water returns to a boil and the sprouts have floated to the surface. Drain through a fine-mesh strainer and combine with the mustard sauce. Set aside.
• To make the dipping sauce, whisk together all the ingredients until the sugar dissolves. Refrigerate until ready to serve.
• To make the filling, remove the stems from the cabbage leaves a by cutting a long V shape along the sides of the stems and discard. Arrange the leaves in a pile and cut into thirds lengthwise, then turn horizontally and cut into 1/8-inch-thick pieces. Mix well with 1/2 teaspoon of the kosher salt in a mixing bowl and let sit at room temperature for 20 minutes (the salt will draw out the excess moisture in the cabbage).
• Meanwhile, lay a piece of plastic wrap on the counter and grate the peeled ginger over it. Pull up the sides of the plastic around the pile of ginger to create a small packet. Poke a small hole in the bottom of the packet with the tip of a knife and gently squeeze over a clean bowl to gather the ginger juices; continue squeezing until you have extracted 1 tablespoon of liquid. Mix with the chicken stock, sake, soy sauce, and sesame oil. Set aside.
• Use a clean towel to wrap one-third of the cabbage and squeeze over the sink to drain, then place the cabbage on a cutting board. Repeat with the remaining cabbage. Roughly chop the drained cabbage and combine with the garlic chives, scallions, and grated garlic in a bowl.
• Remove the pork from the refrigerator and mix well by hand until sticky, being careful to work quickly so the pork doesn't become warm. Slowly mix in the seasoned chicken stock. Once it is well combined, mix in the cabbage, sugar, the remaining 3/4 teaspoon salt, and the pepper.
• To assemble, lay a gyoza skin on the counter. Place 1 scant tablespoon of the filling in the center. Using your index finger, run a thin layer of water along half of the inner rim and press both sides together to create a tight seal, forming the shape of a half circle. Make four tucks along the edge of the dumpling and set upright on a plate or baking sheet to create a flat bottom. Repeat with the remaining gyoza skins and filling.
• To cook, place a medium nonstick sauté pan over high heat and add 1 tablespoon of the vegetable oil. Add 8 to 10 gyoza to the pan, flat side down. When the bottoms have caramelized, in 1 to 1 1/2 minutes, add 1/4 cup of the water and cover with a lid. Decrease the heat to medium and cook, covered, until the water has evaporated, 3 to 4 minutes. Uncover the pan and drizzle 1 teaspoon of the oil on the gyoza and continue to cook until the bottoms become crisp, about 2 minutes. Transfer the gyoza to a serving platter with the browned side on display. Repeat with the remaining gyoza, water, and oil.
• To serve, arrange 5 gyoza on an appetizer plate with the browned side facing up. Place 1/3 cup of the mustard bean sprouts next to the gyoza and serve with 2 tablespoons of the dipping sauce in a cup.