This is what I remember. Dad roasted both in the oven and in the fireplace.
He cut an X in the shell, then placed the whole thing (X side up) on a cookie sheet for the oven. I think they roasted maybe 20 - 30 minutes. The shell sort of opens up from the X so the inside is exposed. When it's cool then peel it, be sure to get the inside brownish skin off too. It will be sweet to taste. Looks a little like a brain. (!)
He did the same thing when roasting on the fire, but used an iron skillet and left the lid on. Seems like about the same time too. Maybe 30 minutes. There was a grate over the coals, and the skillet had a very long handle I remember.
Guess we could look it up.
Sorry Tee, we got a little sidetracked from Sweet Potatoes.