In a large heavy 7 qt. pot, heat oil very hot. Stir in flour. Cook, stirring all the time to make a dark yellow roux. Add onions, bell pepper, celery and garlic to roux cook until vegetables are tender. Stir in tomatoes and tomato sauce into vegetable mixture; then add water. Season with salt and pepper to taste. Bring to boiling, reduce heat to medium and cook 30 minutes. If sauce is too thick, add more water and adjust the seasonings. Cut filets in serving pieces and add to the sauce. Simmer about 20-25 minutes. Gently stir in parsley and onion tops. Cook 5-10 minutes more. Serve over rice.
Cajun Country -- New Iberia, Louisiana