To cook the chicken stir in tomatoes, clam juice, 1 tsp. Cajun spice, salt and chicken. Bring to a boil and reduce heat immediately; simmer uncovered, stirring occasionally, for 10-15 minutes.
In a heavy skillet heat the oil over medium heat. Stir in flour and cook, stirring constantly until sauce is darkened, about 10 minutes.
Stir in celery, pepper, onions and garlic. Simmer 5 minutes.
Stir in tomatoes, clam juice, Cajun spice and chicken. Bring to a boil; reduce heat and simmer uncovered, stirring occasionally, for 10-15 minutes. Add salt and pepper to taste.
Remove from heat and let stand 3 minutes.
While the chicken is cooking, cook the rice according to the package directions, adding 3/4 tsp. to the water. Serve the Etouffee over the rice.