My wife washed and peeled one. Raw it has consistency of a crisp apple but tastes of nothing.
Or maybe I'm coming down with Covid-19?
From what I can gather its an ingredient that is used in Thai stir fries. Its a bit like water chestnuts and is mainly used for texture. As Master Cutler comments it can also be made into a syrup. There is some info here:
How to cook/ use yacon - Maker gardener