Ingredients:

2 1/2 - 3 cups flour
2 tsp active dry yeast
5 tbsp sugar
3/4 cup warm milk
1/3 cup warm water
1/2 tsp salt

Egg wash:
1 egg, slightly beaten with 1 tbsp of water

Filling:
2 cups shredded cooked chicken (i used the leftover of the roasted chicken we had for lunch)
2 pcs chorizo, sliced
1 potato, peeled and cubed
2 pcs salted egg, quartered
2 tbsp cooking oil
4 cloves garlic, minced
1 onion, chopped
4 tsp hoisin sauce
4 tsp oyster sauce
1 tbsp sugar
1/2 cup water
1/4 cup green peas (i have some left over, so I tossed it in as well :) )
2 tsp cornstarch, dissolved in water
salt and ground black pepper , to taste

Procedure:

1. Dissolve 2 tbsp sugar in milk and water. Add in yeast, let stand for about 15 minutes - until bubbly.
2. In a bowl, mix the dry ingredients - sugar , 2 1/2 cups flour and salt. Then add to milk and water mixture. 
3. Kneed the dough. Add flour as needed until it's not sticky. Then place and cover it in an oiled bowl. Let the dough rise for about an hour.
4. While waiting for the dough to rise, prepare the filling. Heat oil in a pan.Saute garlic, chorizo, toss in the chicken and green peas. Stir in hoisin sauce, oyster sauce and water. Add sugar then cornstarch solution. Cook for about 3-5 minutes. Set aside. Let cool.
5. Preheat oven to 180 °C.
6. Now, to prepare the dough, punch it down (yeah as in really do some punching), then roll it and cut into 10 - 12 pieces. Roll each piece into a ball. Then cover with cloth. Set aside for about 10 minutes.
7. Then flatten each roll to form a thin circle. Place a scoop of filling in the centerthen add a slice of egg, gather the edges over the filling, then pinch the edges to secure and seal the bun.
8. Place the buns with the seam upside down in a baking tray. Cover with cloth and let rise for about 15 minutes or until puffy. Brush buns with egg wash.
9. Bake the siopao for about 20 minutes or until it toasts to a nice soft brown.