My DBiL, who loves rutabagas, once tried to make rutabaga pancakes, substituting grated rutabaga in a potato pancake recipe. It was not a hit! ;)
I like rutabaga but we don't grow them in our garden because DH doesn't like them and besides they're very susceptible to root maggots. Never eaten a cooked turnip, just raw. Both ruties and turnips are good raw. Parsnips are yummie cooked with a beef potroast along with onions, potatoes and carrots.

Also living in California, I have to admit that we don't eat them in this house. (but, maybe it's something we ought to try---can never get enough veggies....)