Preheat the oven to 350 degrees F.
Saute the onion, celery, and pepper with 3 tablespoons of the margarine. When wilted, add the catfish chunks and the remaining 1 tablespoon margarine together with liquid crab boil and mix well. As catfish cooks, break up fish with a cooking spoon. Set catfish mixture aside.
In a microwave oven, melt cream cheese on HIGH for 1 minute. Add ketchup, parsley, and pepper and mix well. Fold cream cheese mixture into catfish mixture and add Italian bread crumbs.
Microwave mixture on HIGH for 8 minutes, stirring once halfway through cooking. Cut French bread lengthwise. Place on cookie sheet, sliced side up. Spread catfish mixture on each length of bread. Sprinkle with mozzarella and cheddar mixture.
Bake for 10 minutes, or until cheese is melted and bubbly. Cut into individual slices. Serve and enjoy!
A viewer or guest of the show, who may not be a professional cook, provided this recipe. It has not been tested for home use.