For roux, in a heavy 2 litre saucepan stir together flour and oil till smooth. Cook over medium-high heat 5 minutes, stirring constantly. Reduce heat to medium. Cook and stir constantly about 15 minutes more or till a dark, reddish brown roux forms. Cool.
In a 3.5, 4, 5, or 6 litre crockery cooker place water. Stir in roux. Add sausage, chicken, okra, onion, green pepper, celery, garlic, salt, pepper, and red pepper. Cover; cook on low-heat setting for 10-12 hours or on high-heat setting for 4.5 to 5 hours. Skim off fat. Serve over rice. Makes 6 servings.