Add the pork, bacon, cabbage, chives, ginger, sesame oil, 1/2 teaspoon salt, the sugar, garlic, soy sauce and cornstarch; mix with your hands until combined.
Lightly beat the remaining egg in a small bowl with 1 tablespoon water. Set 1 dumpling wrapper on a clean surface (keep the rest covered with a damp paper towel so they don't dry out). Scoop 1 heaping teaspoonful of the pork mixture onto the center of the wrapper. Dab a finger into the egg mixture and brush along the edges of the wrapper. Fold the wrapper in half and press the edges together to seal, then transfer to a baking sheet. Cover with a damp paper towel while you form the remaining dumplings.
Heat 2 tablespoons vegetable oil in a large nonstick skillet over medium-high heat. Working in 3 batches, add the dumplings and arrange in a single layer; cook until the bottoms start to brown, about 30 seconds.
Add 2/3 cup water, cover and cook 3 minutes. Uncover and cook until the liquid evaporates and the bottoms are crisp and golden brown, about 2 more minutes. Loosen the dumplings from the pan with a spatula and transfer to a serving plate.
Add 2 more tablespoons oil to the pan between batches.
Ponzu Dipping Sauce
Combine 3 tablespoons ponzu sauce, 1 teaspoon soy sauce, 1/2 teaspoon sesame oil and 1 chopped scallion in a small bowl.
