I'm lazy and hate washing pans. I mix half stick of melted butter and couple tbs olive oil in a bowl. Pour over fish, rub in your favorite cajun or blackening seasoning. Put under broiler on top or next to top wrack on foil lined and greased pan. Broil for about 5min, flip and broil other side broil until desired browning.

It's not quite as good as cast iron pan method, but it does not smoke up the house, and you just throw away foil and clean up is done.