1 tablespoon Cajun blackened seasoning mix
1 teaspoon yellow mustard seeds, crushed*
1 teaspoon brown mustard seeds, crushed**
1 teaspoon ground mustard
1 teaspoon dried thyme
1/4 teaspoon salt
1/4 teaspoon pepper
1/4 cup butter, melted, divided
4 (5- to 6-oz.) catfish fillets, patted dry
2 teaspoons red wine vinegar
1 1/2 tablespoons chopped fresh parsley
1. Combine all spice mix ingredients in small cup. Reserve 4 teaspoons of the melted butter in small cup; place remaining butter in shallow bowl. Lightly dip catfish in butter; place on small rimmed baking sheet. Sprinkle with spice mix.
2. Heat large cast-iron skillet over medium-high heat until very hot, about 5 minutes. Add catfish, in two batches if necessary. Carefully spoon 1/2 teaspoon of the reserved butter over each fillet. Cook 3 to 4 minutes or until well-browned but not burned. Turn; spoon an additional 1/2 teaspoon reserved butter over each fillet. Cook 3 to 4 minutes or until fish just begins to flake. Remove; immediately sprinkle with vinegar and parsley.
TIPS *Crush mustard seeds with mortar and pestle, spice grinder or in plastic bag with flat side of meat mallet.
** Brown mustard seeds are smaller but more pungent than yellow mustard seeds. They are common in Indian cooking. If unavailable, substitute yellow mustard seeds.