Enoki mushrooms, their Korean name is “Paeng-ee beosut”. I think they are the cheapest mushrooms in Korea. You can get 3 packs of these mushrooms for 1000 won (US $1.05) at the supermarket. (Sometimes 5 packs for 1000 won.)
This is a picture of the enoki mushroom pack.
![enoki mushroom enoki mushroom](https://mykoreankitchen.com/wp-content/uploads/2006/10/enoki-mushroom.jpg)
How to use : cut off the root system (approximately 4 cm) and wash briefly before use.
You can learn more about enoki mushrooms from wikipedia.