In the same pot add the remaining oil and sauté onion, celery, and pepper until they're soft--about 10 minutes. Add the tomato paste, garlic, Creole seasoning, and basil. Cook, stirring, for a minute or two. Stir in the tomatoes, stock, and bay leaf. Return the chicken to the pot along with the accumulated juices. Simmer on low for 20 minutes. Taste for seasoning and adjust if needed.