First melt a half stick of butter and mix with a tablespoon or so of the Cajun seasoning (below). Pat the fish dry and lay it in the seasoned butter while you heat some oil in a cast iron skillet over medium-high heat. When the oil just begins to smoke, lay the fish in the skillet. Be sure to use plenty of oil so the fish won’t stick. Sprinkle more Cajun seasoning on the fish and cook until the outside is dark brown (just before it goes black). The darker the better!
If you are using store-bought fish, you can pack it in the butter/seasoning mix in a zip-loc bag before you leave and cleanup will be a snap. Just remember to bring some dry seasoning to put on while it cooks.
Cajun Seasoning (or use Cajun Secret):
1 tablespoon sea salt
1 tablespoon garlic powder
1 tablespoon onion powder
1 teaspoon ground black pepper
1 teaspoon cayenne pepper