Heat a large skillet on medium-high heat. Add olive oil until heated. Add onion and red & green bell peppers and saute until soft, about 3-4 minutes.
Add garlic and oregano until fragrant, about 30 seconds and then add the ground beef and seasonings. Break apart the beef with a wooden spoon or masher. Cook until the beef is no longer pink and almost cooked through, about 5-7 minutes. Then stir in the tomato paste.
Add the can of diced tomatoes (no need to drain), uncooked rice, and beef broth. Bring everything to a boil. Reduce to low heat, cover, and simmer for 15-18 minutes until the rice is cooked.
Turn off the heat, give it a stir, and add extra broth if needed. Add the cheddar cheese to the top of the skillet (optional).
