Popularized by the great Cajun chef Paul Prudhomme, blackened fish became a rage around the entire country in the 1980s after he served it at K-Paul’s Louisiana Kitchen, in New Orleans. In truth, frying fish outdoors in this manner had been a Cajun tradition for decades; what Prudhomme did was demonstrate how the smoky ritual could be executed in the restaurant or home kitchen. Of course, the technique has been abused by cooks from coast to coast, with some using the wrong types of fish, others cooking the fish on grills instead of in blazing-hot cast-iron skillets, and still others tampering with strange seasonings that transform the flavor altogether. Here is the original method I learned from Prudhomme at his restaurant and at one front-yard cookout, and believe me, it shouldn’t be modified if you want to see how brilliant the dish can be. Nothing is as succulent as fresh redfish indigenous to Louisiana, but since it’s available only in the most upscale, expensive fish markets, you can also use small fillets of red snapper, pompano, tile fish, or grouper. Do be warned that cooking fish in this manner creates lots of smoke, so if you can get a cast-iron skillet extremely hot outside over an open fire or on a grill, so much the better. (Note: Prudhomme has marketed a seasoning mix called Cajun Magic, available at 1-800-457-2857 or www.chefpaul.com, which contains, and therefore can be substituted for, the seasonings in this recipe.)