Bao buns looks so fluffy and simple to make, but I found them to be quite temperamental at first! My favourite tips for getting perfect fluffy buns, is to use bao flour (low protein), removing the steamer lid very carefully as not to drip condensation back onto the buns and wait a few minutes for the dough to set after steaming before you transfer them to a plate. Once you get the hang of it, you can start forming various shapes with the dough and fill them with delicious fillings!
Sift together the flour, sugar, salt, baking soda and baking powder into a large bowl. Set aside.
Warm the pork fat together with the milk until it reaches 37C or is lukewarm.
Place the dough back into the bowl, cover with a damp cloth and set aside to proof for 1hr.
Meanwhile prepare some 10cm squares of baking paper for the buns to be steamed on.
Divide the dough into 8 portions and pat down to about 1cm thick. Sprinkle a little green onion over the dough. Using your fingers, gently stretch out each portion and give it a twist before twisting it over itself and pinching the ends together.
Place each portion, seam side down, onto a square piece of baking paper. Cover the buns with a damp paper towel and allow to proof for 30mins.
Place buns into the steamer tray, leaving room for them to grow and steam for 6 mins.
Carefully remove the lid without dripping any condensation back onto the buns. Remove the steamer tray from the heat and wait 1-2 minutes before transferring the buns to a plate, this allows some moisture to evaporate and the buns to firm up.