In a small bowl, combine the pepper, garlic salt, Cajun seasoning, and bay leaf and mix well; set aside. In a large pot, heat the vegetable oil over high heat. Add the onions, celery, and green peppers and stir. Add the flour and stir until blended. Add the chicken broth and stir until smooth. Add the tomatoes, tomato paste, and okra and stir until mixed well. Add the hot sauce and seasoning mixture and mix well.
Bring the gumbo to a boil and then reduce the heat to a simmer and simmer for 30 minutes, uncovered. Add the catfish and stir to mix well. Cover the pot and simmer for 20 minutes. Serve with rice.