In a large bowl, combine ground beef, cooked rice, egg, cilantro, garlic powder, onion powder, salt, and pepper.
Mix well and form into small meatballs, about 1 inch in diameter.
In a large pot, bring the beef broth to a boil over medium heat.
Carefully add the meatballs to the boiling broth.
Reduce heat and simmer for about 10 minutes.
Add diced carrots, potatoes, zucchini, and corn to the pot.
Stir in the diced tomatoes and allow to simmer for an additional 20-25 minutes.
Check for seasoning and adjust salt and pepper as needed.
Once the vegetables are tender, remove from heat.
Serve hot, garnished with more cilantro if desired.