Cooked Wheat Flour: Put wheat flour in a small bowl. Pour in boiling water and mix evenly. Cover the bowl for 4-5 minutes. Remove the lid or cover and knead until dough is smooth and even. Use it as cooked dough.
Preparing the dumpling: Combine glutinous rice flour and sugar in a mixing bowl. Make a well and pour in water to mix. Add cooked wheat dough and knead well. Stir in shortening and add wheat flour. Slowly work and knead the mixtures until a dough is formed.
Roll out dough into a long sausage. Cut into even portions and roll each into a small ball. Dust tabletop with a little tapioca flour. Flatten each piece of dough into a thin disc. Fill with a tablespoon of prepared filling. Shape into a half moon and press to seal the edge.
Heat oil in a wok and drop in the prepared savoury dumplings in batches. Deep-fry over low heat until golden brown.
To make filling: Heat sesame oil and fry dried prawns and garlic until fragrant. Add in onion and fry for a while. Stir in the rest of the ingredients and seasoning. Fry till cooked through. Thicken the gravy with starch solution.