1 tsp instant dried yeast
1 tbsp white sugar
120ml warm water
200g high-gluten flour
150g plain flour, plus extra for kneading
1 tsp baking powder
1 tbsp vegetable oil, plus extra for greasing
1 tbsp rice vinegar
Add the yeast and sugar to the warm water and leave for 1 minute to dissolve.
In a large bowl, whisk together the flours and baking powder and then add the oil, vinegar and milk. Then add the water solution and mix well. You want the mixture to come together to form a dough. If the dough is too dry, add 1 tbsp water at a time.
Tip the dough onto a lightly floured surface and knead for 10-15 minutes, or until the dough is smooth. Lightly oil a bowl and add your dough. Loosely cover with a damp cloth and leave for at least 1 hour, in a warm place, to rise. The dough should double in size.
Tip the dough back onto a lightly floured surface and knock out the air in the dough. Knead the dough again for 5 minutes until it is smooth and elastic.
Roll the dough into a sausage shape and divide into 12 small pieces, or 6 large pieces. On a lightly floured surface, roll each piece of dough into an oval shape 1cm thick and then lightly brush the top with oil. Fold the dough in half to create a half moon shape and place onto a piece of greaseproof paper which is 1cm larger that the bao on all sides. Place onto a tray and cover with a damp cloth, and then repeat for the remaining dough.
Leave to prove for another 30 minutes in a warm place. The dough should double in size again.
To cook, bring a saucepan of water to the boil which is just smaller than your steamer so that the steamer sits tightly on top.
Once the water is boiling, carefully place the bao into the steamer tray leaving at least 2 cm between the bao and the side of the steamer to allow them to rise whilst cooking. You may have to cook these in batches.
For smaller bao, steam for 8-10 minutes or until when pressed the dough springs back straight away. For larger bao, steam for 12-15 minutes.
Serve hot stuffed with your choice of fillings.