Well, I do have relatives in southern Louisiana but my handle was given to me by my kids. I love to barbecue and if I am not driving I can usually be found standing very near a grill. As any good BBQ chef knows you gotta sear the meat to lock in the juices. Sometimes I might apply a little irrational exuberance to the searing part with chicken and it comes off sweet, tender, tasty, and properly blackened Cajun style.
While feeding a raft of swim team kids at our house they all had fun with the visual presentation of properly "blackened chicken" and started calling me Cajundaddy. It stuck.
BBQ chicken anyone?