Wash and peel the parsnips. Cut them into approx. 1 inch chunks, Place in a medium saucepan and add water to just cover all of the parsnips.
Simmer over medium heat until most of the liquid has evaporated and the parsnips are very tender.
In a small food processor or blender, Puree the cashews and their cooking liquid until very smooth and there are no chunks.
Use a potato masher to mash the parsnips with the cashew puree and sea salt, season with pepper if desired.