Preheat the oven to 350 degrees Fahrenheit. Score the fish and season with salt and pepper, then place it in a roasting pan.
Make a roux by heating oil in a saucepan, adding flour, and cooking until browned. Add onions, bell peppers, celery, garlic, blue crabs, wine, creole seasoning, and red pepper flakes. Cook until wine reduces.
Increase heat and add tomatoes, seafood stock, tarragon, and bay leaves. Bring to a boil, season with salt, pepper, and Worcestershire sauce.
Pour the Creole sauce over the fish, cover with foil, and bake for 35-40 minutes. Uncover, add shrimp and oysters (optional), and bake for another 15-20 minutes.
Serve with rice, green onions, and lemon wedges.