Preheat the oven to 400°F (200°C). Lightly grease a 9x13-inch baking dish (only if not using an oven-proof skillet).

Heat the olive oil in a large deep skillet over medium heat. Add the onion, red bell pepper, green bell pepper and yellow bell pepper and cook for 5 minutes, stirring often, until softened.

Stir in the garlic and cook for about 30 seconds, until fragrant.

Add the ground beef and cook for 6-8 minutes, breaking it up with a wooden spoon, until browned and no longer pink. Drain off any excess fat.

Stir in the tomato paste, Worcestershire sauce, Italian seasoning, smoked paprika, sugar, salt and black pepper. Cook for 1 minute.

Pour in the tomato sauce, crushed tomatoes and beef broth. Stir well and bring to a simmer.

Stir in the rice, then cover the skillet with a lid and cook for 10 minutes or until the rice is almost cooked through. The liquid should be mostly absorbed at this point.

If your skillet is not oven-proof, transfer the mixture to the prepared baking dish. Scatter the shredded cheese evenly over the top.

Bake for 8-10 minutes until the cheese is melted and bubbling.

Let the casserole rest for 10 minutes before serving.