Steaming is a basic technique in Chinese cooking, and can be done in
2 basic ways:
1. Steamer: essentially a very large pot-like container divided into
layers by porous materials that allow the steam to seep through. We
are all familiar with the bamboo variety, which stack and come in a
variety of diameters; dim sum (Cantonese tapas-style lunch) is served
in these. But you still need to put these steamers in a larger pot
that generates the steam. So someone has invented the fusion of the
two, namely the huge pot subdivided into layers by metal dividers
that have holes in them. Pour water into the pot, bring to a boil,
put the food (either a dish or a bun with a piece of paper
underneath) onto each layer, cover with the lid, and steam for the
required amount of time.
2. Wok: if you have a metal stand (which sometimes comes with the
wok, but are also sold separately in the utensils section), just
place it in the wok, bring water to a boil in the wok, place the dish
on the stand, cover with the wok lid, and steam for the required
amount of time.
N.B.: in both cases, having what I call a dish lifter helps. This
gadget is basically a pair of non-elastic tongs adapted in width and
grip to pick up hot dishes by their edges from a steamer or a wok.
It really has no name, but is also widely sold for a couple of
dollars in any Asian grocery store.