Clockwise from left, enokitake, buna-shimeji, bunapi-shimeji, king oyster mushroom and shiitake (front).

Matsutake mushrooms ($170 for selection shown)

Mushrooms in Asian cooking are used for flavour, aroma, texture and form. Nutrition is always a consideration and in many ways mushrooms are of the more nutritious foods.

Out of the selection pictured above, the shitake in its dried form would be the most commonly used. It's cheap and stores well. Cultivation techniques have ensured a reliable supply of reduced price mushrooms and with the continuous availability of many kinds, the mushroom containing menus can be offered all year rather than on a seasonal basis.

The se of dried mushrooms may not be food that many have had experience with. There's nothing dangerous about he product or difficult in its preparation. Rehydration means soaking in warm water for a specified period before processing further. The soaking water is usually reserved for subsequent use in the cooking process as it tends to be quite flavoursome.

Once rehydrated, the mushrooms should be washed of adhering material such as dirt etc as for fresh mushrooms. Extra water is removed from the mushroom by simply squeezing the body of the mushroom. It never rehyrdrates back to the original product but usually comes out with a flavour more intense than the fresh mushroom.

The dried  funghi are also easy to deal with. These tend to rehydrate quickly ballooning up to five times their dry volume. These generally need to drain for a very short time after rinsing and then process according to your recipes. I'm always conservative with the amount of funghi I rehydrate. I think that it's better to rehydrate a little at a time so you can get an idea of the amount of finished product. Otherwise you run the risk of having to throw out unused material. This isn't so much a cost factor as a convenience factor particularly if you had to make a special trip to a place supplying this material or maybe ordered it online.

Asian culinary mushrooms are safe foods. There are  a couple of funghi which have anti-platelet effects and may be contra-indicated for people taking anti-platelet drugs and anti-coagulants such as warfarin, dindevan or injections of heparin. The reason being is that it may increase the sensitivity of the drugs and cause an inadvertent bleed

Fresh asian mushrooms such as oysters, matsutake etc aren't treated any differently in preparation to familiar field mushrooms consumed in the west. Genearally a quick rinse to wash away adhering dirt and a wipe over so that there is no water damage of the fruit. (This is true particularly where the recipe calls for uncooked fresh mushrooms).

So fresh asian mushrooms should be bought when seen and then find out a recipe to use it.
Dried mushrooms should be bought in moderate quantity and can be mixed in with dried mushrooms for various dishes such as mushroom sautees and mushroom siu chao bao. Dried mushrooms have a shelf life of about a year.