In a large pot combine oil and flour. Cook over medium heat stirring constantly until the roux has browned to a light chocolate color. Add onion, pepper, celery and garlic. Saute for 2 to 3 minutes, stirring constantly. Slowly add chicken broth, and chicken base, stirring as you go. Add water, bay leaves, thyme, basil, parsley, lemon pepper, cayenne pepper, House Seasoning, soy sauce and tomatoes. Cut sausage into 1/2-inch pieces. Add to pot along with okra. Cover pot and simmer for 1 to 1 1/2 hours, stirring occasionally. Add oysters, crabmeat, shrimp and scallops. Simmer for an additional 15 minutes. Serve over hot buttered rice. Sprinkle with file powder on top of bowl and stir in.
Mix ingredients together and store in an airtight container for up to 6 months.
Tip: Add file powder after putting gumbo into individual serving bowls. Adding file into the pot will make the gumbo too thick as File powder acts as a thickening agent.