It is probably quite possible to improvise a steamer by using your existing kitchen equipment, but if you are intending to do a lot of steaming, it is worth investing in a dedicated steamer of some sort. A variety of special equipment for steaming is available. Most common are oval or round steamers, which are rather similar to double boilers, except that the top layer has holes in its base. Steam from the boiling water in the lower pan rises through the holes to cook the food, while the lid on the upper pan keeps in the steam.
Another popular steaming device is a stainless-steel, plastic or aluminum basket that opens and folds shut, rather like a fan. This can be used with an ordinary lidded saucepan. The basket stands on its own short legs to keep it clear of the boiling; it fits inside most saucepans and is particularly suitable for quick-cooking foods as the water underneath the basket would have to be replaced often.
If you want to steam a large fish, a fish kettle is ideal: place the fish on the rack carefully and lower this onto upturned ramekin dishes to hold the rack out of the water. Small pieces of fish can be plate-steamed: put the fish on a lightly buttered plate, season and set the plate on a pan of simmering water or on a trivet inside a frying pan half full of water. Cover the pan and cook the fish for 8-10 minutes.
Chinese cooking also employs steaming. Fish, shellfish and tender cuts of meat, often wrapped in thin pastry or vegetable leaves, and dumplings, are steamed in rattan baskets stacked over a wok of boiling water.
** Asian Recipes