Vietnamese steamed buns with all the fluffiness you would hope for! Handle the dough carefully, so as not to leave dents in the finished buns, and don’t skip the step to brush the dough with oil – oiling stops the buns sticking together (which would make it tricky to get the filling in).
Make the bao buns. Pip the flour, sugar and yeast into a bowl and mix together. In a small jug, mix together the milk, oil, rice vinegar and 3 tablespoons of water.
Pour the liquid mixture into the flour mixture and mix them together with your fingers to create a dough. Add a little extra water, if necessary.
Tip out the dough onto a lightly floured work surface and knead it for 10 minutes, until smooth and shiny. Place it in a lightly oiled bowl, cover, and leave to rise for about 1 hour, until doubled in size.
Meanwhile, make the hoisin sauce. Place the sugar, black bean sauce, soy sauce, rice vinegar, prunes, sesame oil, Chinese five spice and 2 tablespoons of water in a small pan. Bring to the boil, reduce the heat and simmer for 5 minutes, stirring until the sugar has dissolved. Transfer the mixture to the bowl of a mini food processor and blitz until smooth. Spoon into a small bowl and leave to cool.
When the dough has risen, tip it out onto a work surface, knock it back, then sprinkle it with the baking powder and knead it for 2 minutes. Divide the dough into 6 equal pieces.
On a lightly floured work surface, roll each piece of dough into 10 x 6cm oval. Brush the surface of each oval with oil.
Place the wooden chopsticks in the centre of each oval and fold the dough over the chopstick. Place the squares of baking paper onto a baking sheet and top each one with a bun. Slip the tray into a proving bag. Leave to prove for 45 minutes, until doubled in size.
Meanwhile, heat the oven to 200°C/180°C fan/Gas 6 and roast the duck for 40 minutes, until cooked through. While the duck is roasting, cut the carrot, cucumber and spring onions into very fine matchsticks.
15 minutes before the duck is ready, bring a large pan of water to the boil. Carefully slip the chopsticks out of the buns and place 3 buns on their squares of baking paper in each level of the bamboo steamer. Carefully place the steamer over the pan of simmering water and steam for 8–10 minutes, until the buns are puffed up and cooked through.
Shred the roasted duck and toss it together with 2 tablespoons of the hoisin sauce. Carefully prize open each bao bun without fully splitting it and fill it with carrot, cucumber, spring onion and duck. Garnish with the chilli slices and coriander leaves.