So I had two celery roots in my crisper and decided to cube and roast them up. Celery root is the hairless cat of vegetables. While a hairless cat may be a lovable, sweet kitteh, you kind of have to WANT to love it when you see it in its original form. You can see a picture of it (celery root, a/k/a celeraic and not a hairless cat), pre-trimming here - thanks to H-bomb's Flickr pic. In fact the celeraic shown in this photo aren't as gnarly looking as some I've seen.
I trimmed and cubed them and was getting ready to dump the decidedly un-lovely trimmings in the compost bin when I thought, "Hey, would this make good stock?". I heated up some olive oil in my 5-qt. Le Creuset, threw the trimmings in with a pinch of salt and caramelized them a bit. After a while I added a couple of quarts plus some extra of near-boiling water, brought it to a boil, turned it down to a simmer and popped the lid on. That was about 2 hours ago.
I took it off heat at about 3.5 hours in, removed the schmutz and when it cooled down a little, strained it through a quadruple layer of cheesecloth (I scrubbed the celery root before trimming but there was still some dirt in the nooks and crannies - make sure there are no darker particulates in your stock). I thought about reducing it but I like the delicate flavor.