In a large bowl, place flour, milk powder, baking powder, yeast and sugar. In a separate bowl mix the vegetable oil and water. Make a well in the dry ingredients and pour in the liquids. Stir with a spoon and then using your hands, gently knead the dough until it comes together. Tip out onto your work surface and knead for 5 minutes until smooth adding extra flour a tablespoon at a time if the dough sticks to your hands. return the dough to the bowl, cover and rest in a warm place for 90 minutes or until doubled in size
Sprinkle your work surface with flour and tip the dough out. Knead the dough for another 5-10 minutes until you have removed as many air bubbles as possible. Roll the dough out to 1/2 cm thickness. Using your fingers or a brush, lightly spread some oil over the surface of the dough then using your 8cm pastry cutter cut out circles. Remove the excess dough. Fold the round in half and flatten slightly using the rolling pin or a jam jar. Place on a square of baking parchment and either place directly into your steamer basket or on a tray. Ball up your excess dough, roll out again, add some more oil and repeat the cutting process until you have used up all the dough. Cover the tray or basket with a cloth and set aside to prove for 45 minutes
Fill a wok 1/3 full with water and place over a high heat. When the water is boiling, place the steamer basket over the wok and steam for 12 minutes. Turn off the heat (don't lift the lid) and allow the buns to rest over the hot water for a further 5 minutes. If you have more than one steamer basket, you can stack them and the same cooking instructions apply