Rub each side of fillets with Cajun Spice Mix. Heat 2 1/2 teaspoons oil and 2 1/2 teaspoons butter in a large nonstick skillet over medium-high heat. Add 5 fillets; cook for 4 minutes on each side or until fish flakes easily when tested with a fork or until desired degree of doneness. Repeat procedure with remaining oil, butter, and fillets. Serve with lemon wedges.