Add ground beef, diced onion, garlic, and olive oil to a large stock pot. Saute over medium heat 2-3 minutes until fragrant and onions are tender.
Add beef broth, tomato sauce, cajun seasoning, bell peppers and rice and simmer on medium-low heat for 20 minutes.
Taste and add salt and pepper to taste if desired. Top with shredded cheese and serve hot.