• Mix yeast, water, sugar, melted butter, and salt in a large mixing bowl. Slowly mix in flour until it’s fully incorporated and you have a shaggy, very tacky dough, but not wet and sticky.
• Cover the bowl with plastic wrap and let rise for up to an hour in warm place until doubled in volume.
  
• While dough is rising, you can make your filling (see directions below).
• When risen, punch down dough and turn out onto a floured surface. Depending on how much flour you added, it will be somewhat tacky to pretty tacky. Fold it over several times and shape it into a smooth ball, then divide into 12 equal pieces.
• Roll each piece into a ball and flatten it into a disc about 6 inches (15 cm) wide.
• Place a heaping tablespoonful of filling into the center of the disc, wrap the dough around the filling, and firmly pinch it closed over the top of the filling.
  
• Place filled buns (pinched side down) on a baking sheet and loosely cover them with plastic wrap. Let them rest for 1 hour.
  
• Preheat oven to moderate 350°F/180°C/gas mark 4. Beat 1 egg in a small bowl for egg wash and brush on top of each bun.
  
• Bake buns for about 20 minutes, until golden brown. Serve warm.

SIOPAO SAVOURY FILLING (PORK ASADO)

• Heat oil in skillet (frypan). Saute yellow onion, then add garlic and cook for a minute.
• Add pork and brown it.
• Add soy sauce, oyster or hoisin sauce, sugar, and star anise and cook filling until pork is cooked through, about 15 minutes.
  
• Taste and add salt and pepper as desired. Take out the star anise, wash and reuse.
• Place cornstarch and water into a small bowl and stir with fork or small whisk until cornstarch is dissolved.
• Stir cornstarch mixture into filling and cook for an additional 2 minutes. Then remove from heat and cool before making the filled buns.