In a large bowl, combine ground beef, cooked rice, cilantro, garlic, egg, panko breadcrumbs, cumin, oregano, salt, and pepper. Mix until well combined and form into 1-inch meatballs.

Heat olive oil in a large pot over medium heat. Sear meatballs until browned on all sides (about 5 minutes total). Remove from the pot and set aside.

In the same pot, sauté diced onions and carrots until onions are translucent (about 3 minutes).

Add chicken broth and tomato sauce; scrape any browned bits from the bottom of the pot. Bring to a simmer.

Return meatballs to the pot along with any juices from the plate. Simmer for 20 minutes until meatballs are cooked through and tender.

Adjust seasoning if needed before serving hot with additional cilantro.