1. Combine first 9 ingredients in a small bowl; toss gently. Cover and chill 1 hour.
2. Sprinkle blackening seasoning on both sides of fish, pressing down firmly to allow seasoning to adhere to fish.
3. Heat oil in a cast iron skillet over medium-high heat. Add fish, and cook 4 minutes on each side or until fish is medium-rare or to desired degree of doneness.
carbo rating: 3