Instructions For the comeback sauce In a mixing bowl, whisk together all of the ingredients and adjust with lemon juice to taste. Chill until ready to serve. For the fish Heat a cast iron pan, griddle or sauté pan over medium heat, and add the grapeseed oil.Season the fish fillets with the salt and Cajun Creole spice/blackening blend.When the pan is hot sear the fish, presentation side down, until the spices have toasted, 3 to 4 minutes.Flip the fish over, and add the butter into the pan. Continue to cook the fish, basting it with the butter until it’s just cooked through.