Brush plenty of the melted butter all over the fish fillets and season well. Mix the Cajun spice mix with the paprika and rub all over the fish.
Heat a large, dry frying pan until smoking hot. Add the sea bass fillets and cook for 1–2 minutes. Turn over and cook for a further 2–3 minutes until the fish is just cooked through and charred all over.
Drizzle with any remaining butter and serve with lime wedges and a green salad.