The movie had a group of people who are staying in a house in the middle of no where and there is a evil being inside. The movie has a scene where the group is sitting in the living room and talking in front of the fireplace. Little do they know that just up a few feet in the fireplace one of the people's head is being cooked on a small platform that is hanging from the attic. I know that they mention the time requently, so I image that it is important. It may have witches.

I suppose this could be La Casa 4 (aka Witchery) from 1988 with David Hasselhoff and Linda Blair.

It seems to have several elements of this one:

http://en.wikipedia.org/wiki/The_Haunting_(1999_film)