The Principles of Death among the Blood Elves is a book written in 80 BC (1100 years ago) about the rituals surrounding death in communities of blood elves.
The Blood Elves were a sub-species of elves located in what is now the north of Arden. As other elves, they live thousands of years. Death was viewed as a moment to pass on ones knowledge and wisdom to others of the community, and as such, when a blood elf died, their brains were eaten by the youngest members of the community, while the family ate the rest.
Preparing the brains involved making small openings in the skull to poor wine and spices in the skull. After a day of fermenting, the brain is extracted, cut into chunks and fed to the children. The body would be cooked and mixed with various other meats and ingredients favoured by the deceased, and eaten by the family.
The blood elves were already dwindling in population due to a disease in their communities by the time of the writing of this book, and the last communities died out in about 180 AC.