Place a dutch oven or large pot over medium heat, and heat 1 tablespoon olive oil in the pan. To prepare chicken, season with garlic powder, salt, and black pepper. Place the chicken into the pan, and sear each side for 2 minutes, or until golden brown. Remove the chicken from the pan and place it on a plate. Set aside.

In the same pan, add the cubed andouille chicken sausage and cook until lightly brown. When done, add the sausage to the same plate as the chicken, and set aside.

In the same pan, add the remaining olive oil, and saute the onions for 3-4 minutes, or until soft. Add garlic and saute until golden brown, then add bell peppers, mushrooms, and Cajun seasoning. With a wooden spoon, stir the vegetables for about 5-10 minutes, or until they caramelize. Add tomato sauce, chicken broth, bay leaves, chicken, and sausage. Combine all ingredients, and cook for another 20-25 minutes, stirring periodically. Note: chicken is done once the internal temperature reaches 165 F. After 20 minutes, add the cooked rice and stir to combine. Remove the pot from the heat and let stand, covered, for 5 minutes.

To serve, remove the bay leaves, and top with scallions.