Chinese Savoury Doughnut

• extra flour and baking powder, for dusting
• 1 litre (1¾ pints/4 cups)

Put all the dough ingredients into the bowl of an electric mixer fitted with a dough-hook attachment and knead on a low speed for 1–2 minutes. Then turn the speed up to medium and knead for a further 3 minutes, until the dough is smooth. Dust 1 tablespoon of extra flour around the edges of the bowl to help bring the sticky dough off the sides, then tip the dough out on to a lightly floured surf