When television chef Jamie Oliver was in Hong Kong in 2015, he expressed surprise at seeing "doughnuts in congee". He wasn't referring to the round, sweet, glazed doughnuts with holes that Homer Simpson likes so much, but yau ja gwai, also known as deep-fried devils, oil sticks or Chinese crullers.
The fried dough sticks are savoury, not sweet (although some people eat them dipped in sugar), and are often served as an accompaniment to congee or warm salted soya bean milk. In Vietnam, some shops offer them with a bowl of pho.
In addition to leavenings of baking soda and baking powder, yau ja gwai also contain alum and ammonium bicarbonate, which give them an unusual hard, crisp, light texture. The dough is rolled out and cut into long strips, which are then pressed together in pairs before being fried. This gives the fried dough sticks the maximum amount of crisp surface area, and makes them easy to tear in half lengthways.