Heat up the barbecue until it is good and hot.

Once the barbecue has reached the desired temperature now you can begin cooking the fish fillets.

Pour most of the melted butter into a shallow dish (leave around 12 tablespoons of the butter to one side as you will use this later when serving the fish).

After pouring the melted butter into the dish dip each fillet (both sides) in it before then sprinkling some of the Cajun blackening spices over them.

Once this has been done place the fillets on the oiled barbecue grill and cook for about 2 minutes before then turning them over and cooking the other side for a further 2 minutes.

As soon as this time has elapsed or when you feel the fillets are cooked through remove from heat and place on clean plates along with a small bowl in which some of the remaining butter has been placed that your guests can then dip the fish fillets into.