For the dumpling mixture: Place all the ingredients except the wrappers and vegetable oil in a bowl and combine well using your hands.
Using slightly wet hands, shape the mixture into tablespoon-sized balls. With clean and dry hands, hold a wrapper in the palm of your hand and place filling in the centre. Lightly brush wrapper edges with a little water. Traditionally at New Year, the seam is sealed with some pleats (if you make the seam too flat, it is thought to signify poverty).
Fold one side of the wrapper against the other and press together where they meet in the centre. On the right side, lift the top flap over to the left a little, then press down firmly to create a pleat. Repeat again until fully sealed to the end of the right-hand side. Follow the same method on the left-hand side, lifting and pressing down to your right to create the pleats. You should end up with a moon-shaped dumpling.
For the dipping sauce: Combine ingredients and check seasoning.
Set up a large bamboo steamer over a wok of boiling water. Grease the inside of the steamer to prevent dumplings from sticking. Alternatively, use greaseproof paper. Steam dumplings until skins are slightly translucent and filling is cooked through (6-8 minutes).
Place cooked wontons in a dish with a splash of oil to prevent them sticking together. Cover to keep warm while you cook remaining dumplings.
Plate dumplings on a shared platter and serve immediately with dipping sauce.