In a large dutch oven or stock pot, brown the ground beef, onions, and bell peppers. Once browned, drain the grease on a paper towel lined plate and return the beef and vegetables to the dutch oven.
Add the garlic and allow to cook for about 1 minutes.
Add the diced tomatoes, beef broth, and tomato sauce to the pot and stir.
Next, add the salt, pepper, oregano, and uncooked rice.
Simmer the soup for 15 to 20 minutes, or until the rice is tender.
Top each bowl with cheddar cheese and serve immediately.