Cut the fish into 2-inch wide strips and pat them dry. Season the flour with salt and pepper, dredge the fish in it, and pat off any excess flour. Heat 3 tablespoons olive oil in a skillet over medium heat. Saute the fish until it is lightly browned on both sides, about 3 to 4 minutes per side. Drain on paper towels and then put the fish in one layer into a shallow glass dish.
Drain the oil from the skillet, return it to medium heat, and add 3 tablespoons fresh olive oil. Add the onions, bell peppers, and scotch bonnet, if using, and cook until the vegetables begin to soften, about 5 minutes. Add the garlic, thyme, bay leaves, peppercorns, and allspice and cook for another 2 minutes. Pour in the vinegar and water and bring it to a boil. Spoon the vegetables and herbs over the fish and then add the vinegar sauce. Serve hot or let it cool to room temperature and refrigerate for at least 4 hours or overnight.
