Preheat oven to 350 degrees. Score fish on both sides and then season with salt and black pepper and place in a roasting pan.
Pour oil into a large heavy-bottomed saucepan and stir in the flour. Cook over medium heat making sure to keep stirring until roux becomes a deep brown color and has a nutty aroma. Add the onions, bell peppers and celery. Cook for 5-6 minutes and then add garlic, blue crabs, wine, creole seasoning and red pepper flakes. Cook until wine has reduced in half.
Increase the heat and add the tomatoes , shrimp stock, tarragon, and bay leaves. Bring to a boil and season with salt, pepper and Worcestershire sauce.
Pour creole sauce over the redfish and cover with foil. Bake for 35-40 minutes. Remove foil and add shrimp and oysters (if using) around fish and bake uncovered for another 15-20 minutes.
Serve with rice, green onions and a squeeze of lemon.