Quote Originally Posted by Atlas View Post
I think you could roast it whole for a while and then cut it. Mind you I haven't tried this, but that's basically what's done with smaller squash and par-cooking them in the microwave, then cutting them. Since they were free it wouldn't hurt to experiment.
I would vent them a bit by puncturig the skin as deep as possible in a couple of places just in case they decide to explode. Don't ask how I know!