Gather all ingredients.
Stir together condensed soup, dressing mix, Italian seasoning, onion, and garlic in the slow cooker insert. Add chicken and turn to coat. Cover and cook on LOW 5-6 hours or HIGH 3-4 hours until chicken is cooked through.
Remove chicken from slow cooker. Stir cream cheese and Parmesan into slow cooker until cheeses have melted. Stir in lemon juice. Shred chicken and return to sauce. Serve over cooked pasta and sprinkle with additional Parmesan, parsley, and crushed red pepper, if using.
