In a mixing bowl, combine the flour, instant yeast, sugar, and salt with a wooden spoon.
Add ½ cup (120ml) of the warm water and 1½ tbsp of oil. Once combined roughly, continue with your hands. Add additional warm water very gradually, tablespoon by tablespoon (usually it needs another 2-3 tbsp of water - it needs to be not too dry and not too sticky).
Line the bamboo steamer: Cut two circles of greaseproof/baking paper to line each tier of the steamer. Prick lots of small holes in the paper to allow steam through.
Once the dough is ready, on a lightly floured surface use your fingertips to press out the air. Divide the dough into 8 equal pieces and roll into balls. Lightly flour the surface again and leave the balls covered with a kitchen towel for 30 mins.
With a rolling pin, roll the balls out into ½ cm thick oval shapes. Fold each in half and put a small square of greaseproof/baking paper between the two halves to stop them sticking.
Place the folded buns in the steamer for another 30 mins to prove further.
Half fill the saucepan with water and place the steamer (with the buns inside) on top. On a medium-high heat let the water come to a simmer. Don’t open the steamer or you will ruin the buns!
Remove the lid and take the buns out gently.
Serving Size 1 bun