My favorite buy every time I go to plaza was a double patties burger. As usual I was going to buy two orders of burger. Hooppss. I noticed there was a new food stand beside the burger store. The new store is selling siopao etc… The siopao is buy one take one, just like the buy one take one burger. I suddenly had a change of appetite and went to siopao store instead.
All the large siopao are on a large double boiler / steamer. This is necessary to keep them always hot for customer orders. I asked for two orders but I had to wait for 10 minutes. No cooked siopao at the time. The crew said cooking time is approximately ten minutes.
While waiting, the crew was pricking the siopao regularly with a toothpick. I was curious so I asked why. She replied, pricking is necessary to check for doneness. The siopao is ready to serve when the bread never sticks to toothpick.
I never know how to cook siopao yet but I plan to try in near future. I think these two bits of information are good start. The ten minutes steaming time and pricking with a toothpick to check for doneness.