There are some food pairings that just seem meant to be. Peanut butter and jelly. Rice and beans. Brains and eggs.Of course, nowadays, you won’t see brains and eggs on a menu too often, but before concern over the “Mad Cow” outbreak of the early 2000s and other factors shifted our preferences, brain and eggs was a popular breakfast pairing in the American South, up until as recently as the mid-1900s. It was also a common combination in fifth-century Rome, if the most-complete surviving Roman cookbook is any indication. De…