pickled placenta
After your wife gives birth. Search through the pile of bloody afterbirth between your wifes thighs and find the placenta. Take it home, pickle it in an acidic solution, and put in on a shelf and leave it for a decade or so. When your child is around about 10 years old, put the pickled placenta between two pieces of buttered granary bread and put it in you sons lunch box for his school dinner.
"whoah man, whats that shit in your sandwich? It looks like a pickled placenta!"