In a large pot over medium-high heat, cook the ground beef, diced onion, and bell peppers. Crumble the beef as it cooks and continue cooking until the beef is browned and the vegetables are softened.

Add the diced tomatoes, beef broth, oregano, garlic salt, black pepper, and rice. Stir well to combine.

Bring the soup to a simmer, then reduce the heat to low. Cover with a lid and cook for 20–25 minutes, or until the rice is tender.

Ladle into bowls and garnish with chopped parsley if desired. Serve warm.