Ingredients...

For The Rub

1/4 cup smoked paprika
2 TBS dried thyme
2 tsp onion powder
1 1/2 tsp kosher salt
1 1/2 tsp garlic powder
1 tsp fresh ground black pepper
1/2 tsp dry mustard
1/2 tsp ground red pepper

1/2 cup melted unsalted butter
2 lbs grouper fillets (or redfish)
1 TBS canola oil
3 lemons halved

Directions...

Preheat Grill to 400 - 450 (Grill because this will create a lot of smoke)
Preheat heavy cast iron skillet on grill for 15 minutes

In a small bowl mix spices. Pour butter in a shallow dish, coat both sides of fillets in butter, then rub, and rub spices in.

Add oil to skillet - it should smoke - place fish gently in, and cook till browned, about 3-4 minutes. Flip and cook until fish flakes, about the same amount of time, and remove fish. Grill lemons till charred, about 3-4 minutes. Laissez Bon Temps Roulez!

Notes - for added heat I add some loosiana hot sauce to the butter, or 1/2 tsp Slap Ya Mama Cajun seasoning to the rub.