To Make the Bao Dough

1. Heat the plant milk in a saucepan for a minute or until a drop feels slightly warm on the back of your hand. Remove from the heat.
2. Whisk into the milk the yeast and sugar and set aside. A few minutes later the milk should be frothy and smell yeasty.
3. In a medium bowl combine the flours and the fine sea salt. Add the milk mixture and mix well with a spoon until you have a shaggy, sticky dough. Cover the bowl with a damp teatowel and leave for ten minutes.
4. Ten minutes later, turn the dough out and knead for a good five minutes. The dough should be very smooth and not sticky. Drizzle a tiny bit of oil into the bowl and spread around with your fingers. Return the dough to the greased bowl and cover with a damp teatowel. Leave to prove for a minimum of 1 hour or until doubled in size.
5. While the dough is proving make the filling.

To Make the Oyster Mushroom Filling

1. Using a fork, shred the king oyster mushrooms into fine shreds. Set aside.
2. Place a large frying pan over medium heat and add the vegetable oil. Bring to heat and then add the whites of the spring onions, the garlic and the ginger. Fry for a few minutes but don’t allow the garlic to burn.
3. Add the shredded mushrooms and fry for another couple of minutes or until the mushrooms are looking soft and are starting to brown on the edges.
4. Add the soy sauce and cook for a further minute before turning off the heat and adding the hoi-sin sauce.
5. Transfer the cooked mushrooms to a large plate and allow them to cool while the bao dough finishes proving.

To Form the Bao

1. Tip out the proved dough onto a lightly floured surface. Gently push out the larger air bubbles with your finger tips. Roll the dough into a cylinder and then slice into 16 equal discs. Cover the dough with a damp teatowel.
2. Take one disk of dough and, using a rolling pin, roll it into a flat circle around 2.5 inches wide. Pick up the dough circle and place it flat in the palm of your hand. Add around 2 level teaspoons of filling mixture in the centre of the dough circle.
3. Working with your other hand, pinch one side of the dough together to form a small pleat in the edge. Rotate the circle slightly and repeat. Keep pleating until the dough is crimped all around the filling. Pinch the seam together one last time to seal and then set down on a small square of baking parchment. Cover with a damp teatowel and repeat the process until you’ve used all the dough and filling.
4. Once you’ve finished forming all the bao, allow them to rest and prove for a further 20 minutes.
5. Heat up an electric steamer or place a bamboo steamer over a saucepan of water over medium heat. Working in batches, starting with the bao you formed first, steam the buns for 15 minutes. Once steamed, the bao should be puffy and sticky to the touch. Carefully remove the bao from the steamer and set aside to cool for 2 minutes before serving.