Shiitake mushrooms are native to Asia, originally China, and are used extensively in Japanese cooking. They have a tough, fibrous stem that allows its cap to become large in diameter and thick. Most people do not use the stems for cooking but I have known people to use them in stocks or even in vegetarian burgers. Shiitake mushrooms are best when the caps are firm and not too dark. When freshly cooked, they have delicious meaty, earthy taste yet they nearly melt in your mouth.
As a result of modern cultivation practices, they can be purchased fresh in most good produce departments. However, they can get pricey, so shop around. If you are unable to find fresh mushrooms, they dry extremely well and can be purchased in dried form at almost any Asian grocery store.
To prepare fresh mushrooms, remove the stems and lightly wash right before cooking. If the caps are too large, it’s best to cut them into smaller pieces or slice them crosswise. Dried mushrooms must be softened in warm water prior to cooking and give the best results in simmered dishes.
Besides having great taste, shiitake mushrooms are believed to have medicinal beneifits as well; such as helping prevent cancer, boosting the immune system and fighting viruses.