Tree/wood ear fungus/mushroom, called nam meo in Vietnamese, is a popular ingredient in Chinese and Vietnamese cooking. Although it is sometimes referred to as a mushroom, it is a fungus that grows on trees. Nutritionally, it has anticoagulent properties and helps prevent blood in feces, hemorrhaging, and excessive menstrual flow. It is inexpensive and is often sold dried, whole or in strips (like what you see in the picture).
To reconstitute it, simply soak in warm water for about 15 minutes. Cut off any hard ends from the base. I like using pre-cut wood ear fungus for ease.
Tree ear fungus has little flavor but provides plenty of crunch despite different cooking methods. That's why it's prized in soups, egg rolls, or when used in stuffing.
Some of my recipes that use tree ear fungus include:
Canh Bi/Bau Nhoi Thit (Vietnamese Pork-Stuffed Winter Melon Soup)
Cha Gio/Nem Ran (Vietnamese Spring/Egg Rolls)
Cha Gio Bap/Ram Bap (Vietnamese Corn Egg Rolls)
Hot and Sour Soup