Preheat your oven to 400°F (200°C).
In a mixing bowl, combine the ground beef, breadcrumbs, cilantro, Parmesan cheese, egg, chili powder, cumin, garlic powder, salt, and pepper. Mix well until all ingredients are thoroughly incorporated.
Shape the mixture into small meatballs, about 1 inch in diameter, and place them on a baking sheet. You should have around 20 meatballs.
Bake the meatballs in the preheated oven for about 15 minutes, or until cooked through and browned.
While the meatballs are baking, heat olive oil in a large pot over medium heat. Add diced onion, and sauté until translucent, about 5 minutes.
Add the minced garlic and bell pepper, and cook for an additional 2-3 minutes.
Pour in the diced tomatoes with their juices, beef broth, black beans, and corn. Stir to combine, then bring the soup to a simmer.
Once the meatballs are done baking, carefully add them to the soup. Let the soup simmer for another 10 minutes to allow the flavors to meld.
Stir in the lime juice just before serving for a fresh finish. Adjust seasoning if necessary.
Serve hot, garnished with optional toppings such as sour cream, avocado, cilantro, or shredded cheese.