Make dark brown roux with oil and flour. Add onion, bell pepper, and celery and remove from heat, stirring regularly until cool.
Cut up chicken into eight pieces (two legs, two wings, split the breast in half, and split the back) and season with salt, red, black, and white pepper, and garlic powder. Put chicken in stock pot with enough water to cover. Add the roux to the chicken stock and bring the mixture to a boil. Turn down heat and simmer for 45 minutes, skimming the top of the soup as it cooks.
Remove the chicken, debone, and discard bones. Return the chicken to the pot and add the smoked sausage and 1.5 quarts hot water. Simmer for 45 minutes. Add green onions, parsley, and tabasco sauce and check for seasoning. Simmer for another 10 - 15 minutes. Serve over rice.