Preheat oven to 375ºF.
Heat oil in a cast iron or an oven-proof Teflon pan until hot.
Wrap fish in paper towels and gently press to remove moisture from surface. Season fish on both sides with salt and pepper and place in pan with the skin side facing up (although there is no skin).
Cook on high for about 30 seconds then turn heat down to medium and continue to cook for about 3 to 5 minutes. Flip fish and place butter in the pan.
Put the fish in the oven for 3 minutes.
Remove fish from oven and place it on the stovetop with no heat under it and, with a spoon, baste with the butter a few times.
Let the fish rest for about 2 minutes before serving.
Heat vegetable oil on high in a large sauce pan or pot (capable of holding 1 gallon of liquid).
Once oil is hot, add onions and cook, stirring for 1 minute.
Add garlic and cook with onions until fragrant, about 3 minutes. Add bell pepper and celery and cook until all vegetables are soft, about 5 minutes. Add bay leaf and butter.
Once butter is melted, add flour and stir together to form a paste. Add fish stock and whisk to get all the lumps of flour out.
Bring to a boil, then turn down to a simmer, stirring constantly. Add tomato paste and whisk out any lumps. Add cayenne and paprika.
Continue to simmer until flour taste is cooked out and the sauce can coat the back of a spoon, about 20 minutes.
Season with salt and pepper to taste, and finish with all the fresh herbs.
Spoon over drum to serve.