1. Sprinkle chicken evenly with 1/2 teaspoon salt and 1/4 teaspoon pepper. Heat 1 tablespoon oil in a large deep-sided skillet over medium-high heat. Add chicken, and cook in batches, turning occasionally, 10 minutes or until well browned. Remove chicken to a plate, and set aside.
2. Add sausage to skillet, and cook, turning often, for 6 minutes or until sausage is well browned. Remove from skillet.
3. Reduce heat to medium, and add onion, celery, and carrot to skillet. Cook, stirring often, 10 minutes or until softened. Stir in garlic, and cook 1 minute. Stir in broth, and scrape up any browned bits from bottom of skillet. Add tomato, next 3 ingredients, remaining 1/4 teaspoon salt, and remaining 1/4 teaspoon pepper; stir to mix well. Add chicken and sausage. Spoon into a 13- x 9-inch (4-quart) casserole dish.
4. Cover and refrigerate overnight, or combine breadcrumbs and remaining 1 tablespoon oil in a small bowl; stir to mix well. Stir in Parmesan cheese. Sprinkle mixture over casserole. Bake, uncovered, at 350° for 45 minutes or until chicken is no longer pink and crumbs are lightly browned.