Along the path to the Buddhist temple at Chompyeonsa, there are many small vending stalls proffering every Korean delicacy under the sun--including, yes, tree roots!  You don't eat them whole or in a stir fry.  They are brewed into a tree tea of sorts.  You can see the bottles of liquid in the right of the picture! 

Toaster-oven sweet potato (Gogoma in Korean) cake baked in the trusty toaster oven served with a dry, salted cashew caramel and some white chocolate mousse.  There is no recipe.  This one just evolved.