Sorry I missed this back in May. But here's what my South Louisiana friends do:
As you know, leave the scales and skin on the outside on the filet.
Get some Ball's brand Cajun Seasoning. ( nothing else will do)
Several fresh lemons and one lime.
Butter
A pinch of garlic salt.
Cilantro ( The flakes will work)
A 1/2 a handfull of diced onion. ( green ones are best)
Blue cheese or feta cheese crumbles.
In a coffee cup or large glass measuring cup, melt the butter in the microwave. Use at least one stick. DO NOT BURN IT ! This is important ! Most people burn it. Melt it slowly...
Squeeze the juice of one large lemon and 1/2 of the lime in the melted butter. Add a pinch of garlic salt. NOT MUCH !
Add some Ball's cajun seasoning to taste. It's salty, so be careful. Then add a dash of the cilantro flakes and the some diced onion.
Now...cut any red lines out of the fish if it has them.
Squeeze the juice of 1/2 of the other lemon all over it. Sprinkle with Ball's seasoning.
POUR 1/2 of the melted butter mixture over it and put the filet back in the fridge for 15 min.
Take it out, lay the filet on the grill, low heat, skin side down and lay some 1/4 - 3/8 inch sliced tomatoes and lemon slices on top. Sprinkle them with the melted butter mixture.
When the tomatoes are done, the fish ought to be done too.
The tomatoes will droop and get a bit soggy. ( they are the best part of the meal !)
RIGHT before the tomatoes are done, lift them up and sprinkle some blue cheese or feta cheese crumbles over the fish. Let it melt.
Reheat the remaining butter mixture in the nuke. Pour the rest it over the fish and veggies just before serving...then squeeze some lemon and/or lime juice over it all.
Keep the Ball's container handy, you might want more as you eat !
You will FIGHT over the tomatoes...so use plenty of them.
You can buy Ball's general purpose cajun seasoning online for about $2.50 a can. Buy the yellow shaker can. It goes a long way.
DO NOT USE TONY's ! It's NOT nearly the same thing ! Ball's imparts a unique flavor when cooked. Tony's ruins it.
P.S. If the fish is big enough, we chop some green onions up and lay them on the fish too.
_________________________

This country has been Ailin' for PALIN for a long time.