Mashed Celeriac / Celery Root

I made celeriac like I would mashed potatoes (with butter and milk). It was ok. It doesn't mash up easily like potatoes do, so I used the food processor. I liked it for the first few bites, but it isn't my favorite thing to eat by itself. I'd prefer it mixed in with potatoes. It would probably be good as the topping on shepherds pie though.