Spray 3- to 4-quart slow cooker with cooking spray. Arrange chicken in bottom of slow cooker. Top with garlic, basil, oregano and pepper.

In separate bowl, stir together Alfredo sauce, tomatoes and tomato sauce until well combined. Pour mixture over chicken.

Cover; cook on Low heat setting 5 to 6 hours.

Ten to 15 minutes before serving time, cook pasta as directed on package. In small bowl, stir together cornstarch and water; stir into mixture in slow cooker. Increase heat setting to High; cook uncovered 5 to 10 minutes longer.