Heat olive oil in a large pot over medium-high heat.
Add ground beef and onion, cooking until beef is browned and onion is translucent.
Drain excess fat from the pot.
Add the chopped bell peppers and garlic, sautéing for 4 minutes until slightly softened.
Stir in the diced tomatoes, tomato sauce, and beef broth.
Add oregano, basil, salt, and pepper.
Bring to a boil, then reduce heat to low and simmer for 25 minutes covered.
Stir in the pre-cooked rice and simmer for an additional 5 minutes to incorporate flavors.
Adjust seasoning and serve hot.