In a large skillet, cook turkey and onion over medium heat until meat is no longer pink, 8-10 minutes, breaking it into crumbles; stir in chili seasoning. Transfer to a 3- or 4-qt. slow cooker. Pour tomatoes and tomato sauce over turkey., Cook, covered, on low 2-3 hours or until heated through. Stir turkey mixture to combine. Top with beans. Sprinkle with cheese. Cook, covered, 5-10 minutes or until cheese is melted. Top with chips. If desired, serve with sour cream, minced cilantro and additional onion.