Add oil to a large pot or Dutch oven over medium-high eat. When the oil is hot, add the bell pepper, onion, celery and garlic to the pot. Cook until fragrant, about 3 minutes. Add the chicken, andouille, and tomato paste. Stir around the mix with the other ingredients and break up the tomato paste. Add the white rich and stir it around until lightly toasted. Stir in the chicken broth, diced tomatoes, Cajun seasoning, and bay leaf. Cover, and let it cook over low heat for 30 minutes, or until rice is cooked through and the liquid has been completely absorbed.* Stir every 10 minutes or so to prevent the rice from sticking to the bottom of the pan. Serve hot!