Soy milk and Mantou buns

• 100 g dried soybeans

Dough

• 30 g oil, plus extra to grease
• 200 g milk
• 70 g white sugar
• 2 tsp dried instant yeast
• 2 ½ tsp baking powder
• 400 g plain flour, plus extra to dust
• ¼ tsp sea salt

Soy milk and steaming buns

• 1250 g water
• ½ tsp grapeseed oil
• 50 g sugar, to taste