In a medium bowl, combine the beef, egg, onion, pickle, parsley, bread crumbs, salt and pepper. Roll mixture into 2-inch balls. In a large skillet set over medium-high heat, brown the meatballs in olive oil. Transfer the meatballs to a slow cooker.
Discard any fat from the pan and return to heat. Add the red wine to the hot pan and scrape up any browned bits from the bottom. Allow the wine to cook and reduce by half.
In a small bowl, whisk together the flour and beef broth. Stir the mixture into the wine, then pour over the meatballs.
Cover and cook on low setting for 4 hours. Serve meatballs and sauce with rice, potatoes or pasta.