Place first 5 ingredients (lean ground beef through egg) in a large bowl.
Using your very clean hands, blend thoroughly then form mixture into golf ball sized meatballs; place them in a slow cooker.
In a large bowl, combine remaining ingredients (tomatoes through black pepper); pour mixture over meatballs and gently stir to combine. Cover and cook on LOW for 6 hours or until meatballs are forktender and sauce has thickened.