Preheat and Sauté: First, preheat your oven to 200°C (180°C fan). Heat the olive oil in your ovenproof skillet over a medium heat. Add the chopped onion and cook for 5-7 minutes, until softened and translucent. Add the minced garlic and cook for another minute until fragrant.

Brown the Chicken: Add the chicken cubes to the skillet. Season with a pinch of salt and pepper. Cook for 4-5 minutes, stirring occasionally, until the chicken is lightly browned on all sides. It doesn't need to be cooked through at this stage.

Add Rice and Liquids: Stir in the uncooked long-grain rice, making sure to coat it in the oil and chicken juices. Cook for one minute. Pour in the hot chicken stock and the milk. Add the Dijon mustard and dried thyme, then give everything a good stir to combine.

Simmer: Bring the mixture to a gentle simmer. Once it's bubbling, reduce the heat to low, cover the skillet with a lid, and let it cook for 15 minutes. Stir it once or twice during this time to prevent the rice from sticking to the bottom of the pan.

Incorporate Broccoli and Cheese: After 15 minutes, the rice should have absorbed most of the liquid. Remove the lid and stir in the broccoli florets and about two-thirds (around 170g) of the grated cheddar. I find that stirring gently but thoroughly ensures the cheese melts evenly into the sauce. Season with salt and pepper to your liking.

Bake to Perfection: Smooth the top of the rice mixture with the back of a spoon. Sprinkle the remaining grated cheese evenly over the surface. Transfer the skillet to the preheated oven and bake, uncovered, for 10-15 minutes, or until the cheese is melted, bubbling, and starting to turn golden brown.

Rest and Serve: Carefully remove the skillet from the oven. Let it rest for 5 minutes before serving. This allows the sauce to settle and thicken slightly. Garnish with fresh parsley, if you like, and serve hot.