Shred them up with equal amounts of potato and carrot, mix in some egg and enough flour to bind it all together and then make "potato pancakes". include any herbs you like, a little salt and some pepper to taste. Pan fry till golden brown.
Parsnips also work well in a fritter made with amaranth.
On occasion I'll use my peeler to make parsnip ribbons, which I tangle into loose balls and then deep fry til crispy. Tastes awesome with a honey mustard dressing.
Of course they are great in hearty winter stews with beef, venison or other four legged red-meat beasts. Add onions, carrot, celery, potato, greens of some sorts, and a little tomato if you like. Can't go wrong adding a little red wine too. salt, pepper, thyme, oregano, rosemary, bay. all that good stuff. This is a good one for using up soup bones.
I liketo harvest one third of my parsnips just before the ground freezes. I get the rest in the spring just as soon as I can get back into the ground. I always leave a few in the garden to flower. they have a really nice flower and also produce a lot of seed. If you can find and open pollinated variety of parsnip, its an easy one to keep going year after year.
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.