Combine the chestnuts, sliced scallions, mince, 1 tsp sesame oil, soy sauce, 1 clove garlic and 2 tsp ginger in a bowl. Place a heaped teaspoon of the mixture in the centre of each wrapper.
Brush the edges of the wrapper with a little water. Fold in half to make a semi-circle shape and press the edges together. Repeat with remaining mixture.
Heat half the vegetable oil in a large frying pan over a medium heat. Add half the gyozas and cook for 1 minute on one side or until the bases are browned. Add ¼ cup water to the pan. Reduce the heat to low. Cover with a tight-fitting lid and steam for 3 minutes. Repeat with remaining vegetable oil and gyozas.
For the dipping sauce, slice the remaining scallions. Combine with remaining sesame oil, garlic and ginger in a small bowl. Add the teriyaki sauce and brown sugar and stir well to combine.
Serve gyoza with dipping sauce.
Notes
Yield: Makes: 20 (4 or 5 per serving if a meal).
Recipe by The Taste Place at https://www.thetasteplace.com/steamed-pork-dumplings-gyoza/