Preheat your oven to 180°C (160°C fan) and have a 9x13 inch (or similar size) baking dish ready if your skillet isn't oven-safe.

Heat the olive oil in a large, deep skillet or Dutch oven over a medium heat. Add the chopped onion, carrot, and celery. Sauté for 8-10 minutes, stirring occasionally, until the vegetables have softened and the onion is translucent. Add the minced garlic and cook for another minute until fragrant.

Increase the heat to medium-high and add the beef mince to the pan. Break it up with a wooden spoon and cook for 5-7 minutes until it's thoroughly browned. Getting a good colour on the meat is key for flavour. For an expert browning technique, you can read more at Serious Eats. Once browned, drain off any excess fat from the pan.

Stir in the smoked paprika and dried oregano, cooking for 30 seconds to toast the spices. Pour in the Worcestershire sauce, the tin of chopped tomatoes, and the hot beef stock. Give everything a good stir to combine, scraping any browned bits from the bottom of the pan.

Bring the mixture to a gentle simmer. Add the uncooked rice and stir it in well. Season generously with salt and freshly ground black pepper.

Reduce the heat to low, cover the skillet with a lid, and let it simmer gently for 15-20 minutes, or until the rice has absorbed most of the liquid and is nearly cooked through. I find that stirring it once or twice during this time prevents the rice from sticking to the bottom.

Remove the skillet from the heat. If it’s not oven-safe, transfer the mixture to your prepared baking dish.

Sprinkle the grated mature cheddar cheese evenly over the top of the casserole.

Place the dish in the preheated oven and bake, uncovered, for 15-20 minutes, or until the cheese is completely melted, golden brown, and bubbling deliciously around the edges.

Let the casserole rest for 5 minutes before serving. Garnish with fresh parsley if you like.