a large bowl, combine the gluten-free flour, tapioca flour, glutinous rice flour, salt and xanthan gum.
Gradually add the boiling water while mixing until a dough forms. Knead until smooth and pliable. Cover and leave to rest while preparing the filling.
In a separate bowl, combine the ground pork, gluten-free soy sauce, gluten-free oyster sauce, ginger, garlic, salt and egg. Mix until well combined.
Divide the filling into approximately 25 equal portions and shape into small balls.
Divide the dough into 25 equal pieces. Roll each piece into a thin, round wrapper, slightly larger than the filling balls.
Heat a little oil in a non-stick frying pan over medium heat. Place the filling balls in the pan, leaving some space between them.
Place one dough wrapper over each filling ball, gently draping it over the top and sides without folding or sealing.
Add a splash of water to the pan and cover immediately with a lid. Steam for approximately 10–12 minutes, or until the pork is fully cooked and the wrappers are tender.
Remove the lid and allow any remaining water to evaporate. Cook briefly until the bottoms are lightly golden.
Serve warm with gluten-free soy sauce or your favourite dipping sauce.