1. Place chicken in a deep skillet with enough cold water to cover; bring to boil and cook 2 minutes. Remove from heat; cover and let stand 40 minutes. Strain broth into a large bowl and reserve. Remove chicken. When cool enough to handle, remove meat and tear into large pieces, discarding skin and bones.
2. Heat oil in large Dutch oven over medium heat. Add flour and cook, stirring constantly, until mixture becomes a nutty brown color, 15 minutes. Add onions, green bell pepper, and celery. Cook, stirring occasionally, until vegetables are just tender, about 10 minutes. Add garlic and cook 30 seconds more.
3. Gradually whisk in 4 cups of the reserved chicken broth. (Cool remaining broth. Cover and freeze for another use.) Add chicken meat, salt, thyme, and red pepper, if using; bring to boil and simmer 10 minutes. Add sausage and okra; continue to cook until okra is tender, 12 to 15 minutes more. Serve over rice. Makes 6 servings.