You can find fresh water chestnuts (which need to be peeled) in the vegetable section of Asian supermarkets. Vacuum-sealed packs of peeled water chestnuts are often sold in the chilled or frozen ...
I like to pick a protein, throw it in a skillet with some vegetables ... frozen vegetables. However, I wouldn't go out of my way to pick up a bag. Finally, I moved on to the Trader Joe's Asian ...