Add the cooked turkey, carrots, celery, onion, stock, turkey gravy mix, onion powder, garlic powder, poultry seasoning, and black pepper to your slow cooker.
Cover and cook on low for 6 hours or high for 4 hours.
Add the rice to the slow cooker one hour before serving, stir, and cover.
Right before serving, stir in the cream.
Garnish with parsley and serve.
