What is your opinion on offal? The caveman would go for these first due to their high nutritional content. Personally i enjoyed anything from pate to bits of tripe in thai noodles before i changed my lifestyle.
If prepared in a healthful way, then there’s nothing wrong with it if you enjoy that kind of thing.
Related note: I think it was Poliquin who talked about how primitive man’s main source of omega-3 may have been brains more-so than fish.
Related article for those who have no idea what offal is: http://www.marksdailyapple.com/organ-meats/