Whilst the barbecue is heating up place the catfish fillet on to a piece of aluminum foil that is large enough that when you fold the edges up it turns into a makeshift pan.
Now place the fish in the aluminum foil on to the barbecue and them pour over the other ingredients and let the catfish fillet cook them until it is done.
On average the fish should be cooked in about 4 to 9 minutes depending on how hot the barbecue is and what the weather is like.
It is important that you watch the fish carefully whilst it is cooking otherwise it could become over cooked very easily.
You will know when the fish is cooked because the edges of it start to turn up and become crispy.
But don’t rely on this solely for telling you that the fish is cooked you should check to see if the middle of the catfish fillet has turned opaque.