In a large skillet over medium heat, brown the lean ground beef until it is no longer pink. Drain off any excess fat.
Transfer the browned beef to your Crock-Pot. Add the diced onion, red bell pepper, minced garlic, salt, black pepper, Italian seasoning, dried parsley, crushed tomatoes, low-fat milk, heavy cream, and beef broth. Stir well to combine. Cover and cook on low for 6 hours.
About 15 minutes before serving, stir in the uncooked elbow macaroni. Cover the Crock-Pot and cook until the pasta is tender and has absorbed most of the liquid, about 15 minutes.
Finally, stir in the shredded cheddar cheese until melted and well mixed. Garnish with fresh parsley when serving.