Homemade Dumplings

Make the dough: In a large bowl, combine flour, cornstarch, and salt. Pour in boiling water and stir with chopsticks or a wooden spoon until moisture is mostly absorbed. Add in room temperature water and continue to stir until a shaggy dough forms. Using your hands, knead dough until cohesive and smooth and no dry spots remain, 10 to 15 minutes. Cover and let rest for 30 minutes to 1 hour. Meanwhile, make the filling: In a medium bowl, toss to evenly combine cabbage with salt. In a large bowl, using chopsticks or a wooden spoon, stir together pork, ginger, garlic, white pepper, black pepper, soy sauce, and sugar. Keep vigorously stirring in one direction until the mixture turns into a smooth paste, about 4 minutes. Add in shrimp, mushrooms, green onions, sesame oil, and cabbage mixture, and stir until evenly combined. Transfer to the refrigerator to chill while dough is resting. Make dipping sauce: In a small bowl, stir together all sauce ingredients. Set aside until ready to serve. Make dumpling wrappers: On a very lightly floured surface, divide dough in half and roll each half into a 1”-thick rope. Cut each rope up into twelve 1” pieces, rotating the rope 90° after each cut. Place each piece of dough cut-side up, then flatten with the heel of your palm. Using a rolling pin, roll each piece of dough into a 3½” disc. Keep wrappers loosely covered with a kitchen towel or plastic wrap to prevent drying out. To assemble: Place a tablespoon of filling just below center on each wrapper. Fold top half of the dough over bottom half and pinch border to seal. Alternatively, pleat dumplings by making small folds and pinching firmly to seal the edge. Place on a cutting board or baking sheet lightly dusted with flour. Repeat with remaining dough and filling. In a large pot of boiling water over medium-low heat, cook dumplings in batches until they float, 4 to 5 minutes. Transfer to a plate and repeat with remaining dumplings. Serve with dipping sauce on the side.