To make the dressing, mix together the kecap manis, chilli oil, garlic, spring onion, Chinkiang and black pepper.
To make the wonton filling, mix together all of the ingredients in a bowl.
Make a paste by combining a little flour with just enough water to make a medium thick paste. Use 1 teaspoon of wonton filling for each wonton skin. Fold it into a triangle, then fold the bottom up towards the end; finally fold the left side towards the right side and seal with the flour and water paste. Round dumpling skins simply need to be filled, folded in half and sealed with the flour and water paste.
Cook the wontons in rapidly boiling water for 3 minutes. Remove from the water, drain and drizzle with the dressing.