The first time I encountered bluefish was in the Massachusetts kitchen of my friend Jill. Her famously unflappable son John was practically beside himself with anticipation of diving into one of the fillets his mom had prepared. I had never heard of bluefish, which are indeed blue, both outside and in. They're an east coast fish, we don't have them on the west coast. Their season is short and they spoil very quickly, so you have to get them fresh and eat them right away.