1. In a large stock pot, bring water, carrots, potatoes, onion, salsa, and bouillon cubes to a boil. Reduce to a medium simmer, stirring occasionally, approximately 10 minutes.
2. Mix the beef, breadcrumbs, and milk together in a bowl. Form into 1-inch meatballs, and drop into boiling broth. Once soup returns to a boil, reduce heat to medium-low.
3. Cover and cook 20 minutes, or until meatballs are no longer pink in center and vegetables are tender. Serve with sprinkled cilantro for garnish.