Mix the wheat starch with the water until it forms a dough.
Pour the glutinous rice flour into a new bowl and make a well for the sugar and wheat starch ball to go in the center.
Add the remaining water in and dissolve the sugar and wheat starch dough by messaging them with your hands. When mixed together, knead it into the glutinous rice flour until it forms a larger dough then work in the oil until incorporated.
Let it rest in plastic glad wrap while you work on the filling.
Dice the pork belly into 0.5cm (0.2") pieces and marinate with the pepper, salt, light soy sauce and 2 tbsp starch water.
Finely chop the rehydrated shrimp, scallops, shiitake mushrooms, pickled radish, water chestnuts, purple shallots and ginger.
Add oil to a pan on medium heat and brown the purple shallots and ginger.
Turn the heat up to high, add the mushrooms, scallops, shrimp and water chestnuts in to stir fry for 2 minutes.
Add the pork belly in along with the five spice powder, sugar, salt, pepper, oyster sauce, shaoxing rice wine, sesame oil and starch water. Cook for 5 minutes or until completely cooked, then set aside to cool.Note: Make sure to mix the starch in water until it becomes a slurry and pour it in at the very end.
Take the dough out and work it until it is flexible. If it is too dry, knead 1/2 tbsp water in at a time to get the desired consistency.
Roll the dough into a long log and divide it into 15 segments.
Roll the dough into a ball and flatten it using your hand then gently stretch the rim until it is 10cm (4") wide or large enough for the filling.
Add 1 tbsp of the cooked pork in the center of the dough.
Bring the left and right sides together and pinch the join close from top to bottom until it encloses the filling.
Roll the dumpling until it forms a long round ball.
Set your fryer up and fry the dumplings on medium heat for 5 minutes or until they start to brown. Just before they're ready, increase the heat to high and fry until golden.
Serve the Ham Sui Gok fresh and hot as is!