Parsnips are awesome. They are not really all that well known here in the Netherlands, so I've been enjoying introducing them to people.
Roast
chicken with roasted parsnips (and other roast veg) is pretty hard to beat.
Leave them in the ground until the frost gets to them, they get much sweeter then. They can stay in the ground for a good long time actually, (climate depending).
Depending on your type you may want to get rid of some, or most of the core, which can be woody in some varieties. Just cut lengthways down the parsnip and the again down the two halves. The core is then easy to cut away with a knife. You don't need to get all of it, so a quick swipe will do.
Rus's Roast veg Recipe:
Shove a large shallow tray with a glug of oil into a 180c (about 350f in old money)
oven and preheat it for 15 mins or so.
Chuck the parsnips and/or beets (pieces or small wholes), turnip, sweede, pumpkin, a couple of small onions, and sweet potato, plenty of salt and pepper, a couple of whole twigs of rosemary and a garlic bulb or two. Stir it around to coat it all with the oil and seasoning and roast for 30 mins or so, turning once or twice.
Remove from the oven and enjoy with a glass of red wine, good company and candlelight.
The trick is not to crowd the veg too much or they don't crisp up that well, they tend to steam (still delicious though) and to remember that they don't take as long as roast potatoes do.