In a large bowl, combine and whisk together the glutinous rice flour, tapioca flour, rice flour, xanthan gum and salt. Make a well in the middle of the flour mixture.
Pour 1½ cup (375ml) of water, extra virgin olive oil and vanilla extract into the well in the bowl, stir and combine the flour then add in the rest of the ¼ cup (62.5ml) water gradually as you hand knead the dough until you have a smooth and slightly sticky dough. Add the rest of the 3 tablespoons water 1 tablespoon at a time if required.
Divide the dough into 2 equal portions. Seal in ziplock bags and let the dough rest on the benchtop for ½ hour.
For the fillings:
Combine and mix well all the ingredients for the filling in a large bowl. Set aside.
For the wrappers:
Dust the work surface and rolling pin with some gluten free rice flour.
Remove 1 bag of dough and divide the dough into 2 equal portions again.
Work with 1 portion at a time, divide the dough equally into balls (around 23g/0.8oz each).
Flatten each ball into a disc or patty. Use the rolling pin to roll each ball into a 3 inch round wrapper.
For stuffing the wrappers:
Spoon 1 tablespoon of the filling onto the middle of each wrapper. Wet the edges of the balls with some water and carefully press and seal the edges together. Press until the edges are thin out.
With your fingers, gently press down on the filled wrappers to flatten the base.
Place on a tray until ready to steam.
For the dipping sauce:
Combine, whisk and mix well all the ingredients for the dipping sauce in a medium bowl. Set aside until ready to serve.
Garnish with some spring onion, red chilli and ginger before serving.
For the blanched choy sum:
Heat up the pot half filled with water, add 2 tablespoons of extra virgin olive oil, then blanch the choy sum on low heat for around 2 minutes or until choy sum turns bright green, drain water and set aside.
For cooking the dumplings:
Place a steaming rack in a wok and fill the wok with half full of water and bring to a rolling boil.
Brush a large plate lightly with some extra virgin olive oil, then place the dumplings on the plate and brush lightly with some extra virgin olive oil.
Steam the dumplings for 12 minutes or until translucent.
Repeat until all the dumplings are cooked. Steam the dumplings in 5 batches.
Serve with the dipping sauce, blanched choy sum and garnish with some spring onion, red chilli and ginger. You can also serve the dipping sauce as a drizzle sauce over the dumplings.
If you want to freeze some of the uncooked dumplings, place them on a large plate or tray and freeze in the freezer. Once frozen, store them in a ziplock bag in the freezer.