Enoki mushrooms, their Oriental name is “Paeng-ee beosut”. I believe they are the most inexpensive mushrooms in Korea. You can obtain 3 packs of these mushrooms for 1000 won (United States $1.05) at the grocery store. (In some cases 5 packs for 1000 won.)
This is an image of the enoki mushroom pack.
Exactly how to utilize: remove the origin system (around 4 centimeters) as well as clean briefly prior to usage.
You can discover more regarding enoki mushrooms from wikipedia.