400g chestnut mushrooms, shredded into thin strips
Spring onions, finely chopped
1 tbsp ginger
1 tbsp mirin
1 tbsp soy sauce
4 tbsp hoisin sauce
To make the dough, mix 1 tbsp of sugar and the yeast with warm water and allow to rest for 10 minutes until slightly foaming. Mix flour, cornflour, remaining sugar and salt in the bowl of a stand mixer. Add the yeast mixture, oil and vinegar and mix for 5 minutes until a smooth dough form. Place in a lightly oiled bowl and cover. Leave to rise for an hour and a half or until doubled in size.
Meanwhile, heat the oil in a frying pan. Add the mushrooms and cook until coloured. Add the spring onion, ginger, soy sauce, mirin, hoisin sauce and fry for a further 2 minutes. Take off the heat and allow to cool slightly.
Once the dough has doubled in size, take it out of the bowl and punch out the air. Mix the baking powder into the dough and knead to incorporate. Roll into a sausage shape and cut into 6 evenly sized pieces.
Roll each piece into a ball and fill with the mushroom filling. Pleat around the edges, bringing in the sides as you go and then pinch and twist the top to seal. Place each bun on a piece of baking paper and steam for 10 minutes on a medium heat.