sometimes ill do as Alix said, but Ill use a 50/50 rutabaga to carrot ratio, then mash with butter, salt ( sometimes a little cream and a bit of sugar too).
cook and mash with potatoes...the flavors go so well together. Roast with olive oil and thyme with other root veg like celery root and sweet potato. Cook on its own as others above say. Very good. also a great soup veg!
I love rutabega. It's my favorite side dish at Thanksgiving dinner. I like mine mashed with butter and a bit of brown sugar. It's also great grated raw into slaws. My eldest sister made some potato soup one time, very creamy, with little chunks of diced rutabega in it. It change the whole nature of the soup, made it much better IMHO. I also love to use it in New England Boiled Dinner, and of course in that peculiarly Michigan filled pastry, pasties. It's also great in stews, expecially with beef or venison. Loooove rutabega. By the way, jsut so's ya knows, it's a cross between a turnip and cabbage, hensc its blend of those two flavors.