Edible mushrooms have been a vital source of nutrition for Homo sapiens for thousands of years. Millenia before humans began farming they foraged for wild mushrooms as they wandered forests and grasslands. Under the proper conditions mushrooms grow quickly in great abundance; to this day they are sought for their exceptional flavor, nutrients and health promoting qualities.
Hoshi Shiitake (literally "dry wood mushroom") are among my most treasured kitchen staples, especially during cool weather when my thoughts turn toward warmer fare. A few shiitakes can add almost magically delicious depth and complexity (umami) to simple vegetable dishes.
Although produce markets offer many varieties of fresh mushrooms, I much prefer the dried ones, which are far more flavorful and can be conveniently stored for months without any loss of quality or nutrients. I don't think of dried shiitakes as a lesser substitute for fresh; they are simply in a category of their own with unique culinary characteristics.
Many groceries sell packaged dried shiitakes. Look for those which have thick, plump caps and which display the characteristic markings seen in the photo above. A one pound package of shiitakes will make many meals; most recipes require only a handful at most. (Sliced dried mushrooms should be avoided, as their quality is inferior).
Dried shiitakes must be re-hydrated before cooking; this requires a bit of planning but is simple to do. Rinse the mushrooms in cool water to remove any extraneous material, then place in a glass or ceramic bowl with enough fresh water to cover. I rarely soak them for more than one hour but some sources recommend up to eight hours for best flavor and texture. They can be stored overnight in the fridge while soaking.
Once the mushrooms have softened, remove from water. Squeeze one at a time with your hands to remove remaining liquid. Don't discard the soaking water; it is highly flavorful and can used as stock. Place the mushrooms on a cutting board and using a sharp knife, slice to the desired thickness. If the stems are very tough, set them aside for use in long simmered dishes.
Hoshi shiitake have a multitude of uses. In Japanese cooking they appear in miso soup and rustic vegetable stews, and are added to rice dishes. I have used them in the mushroom barley soup made by my mother and grandmother - although they prepared it with the highly prized aromatic dried Russian mushrooms which were always kept on hand. Recently I have added thinly sliced shiitakes to black beluga lentils and also to home made tomato sauce, with excellent results.
Remove dried shiitakes from their original package, place in a clean glass jar and store in a cool dark place. They will keep for many months, always on hand for a little culinary mushroom magic.