In a large bowl, combine ground lamb, garlic, 1 teaspoon of the salt, 1 a teaspoon of the pepper, the red onion, egg, and Worcestershire. Blend thoroughly with your very clean hands then place mixture in a large zipper-topped plastic bag. Seal bag and refrigerate.
Place the next 6 ingredients (broth through rutabaga) along with remaining salt, remaining pepper, the thyme, rosemary, and white pepper in a large slow cooker.
Cover and cook on LOW for 8 to 10 hours. 1 hour and 30 minutes before the soup is finished preheat oven to 375 degrees.
Pull lamb mixture from refrigerator and form into 1 1/2-inch meatball; place them on a baking sheet and bake for 15 to 20 minutes. Transfer meatballs to the soup in the slow cooker. Cover and cook for 1 hour.