Preheat the oven to 140°C bake. Generously butter a 9 × 13-inch casserole dish.
Pour the unwashed rice into the prepared dish and spread evenly.
In a saucepan, gently warm the milk, cream, sugar, vanilla essence, salt, and nutmeg until warm. Do not let it simmer or boil.
Carefully pour the warm milk mixture over the rice.
Place the dish into the oven uncovered and bake for 30 minutes.
Remove the pudding from the oven and give it a gentle stir, then return it to the oven for another 1½ hours, or until the rice is tender and the top has developed a golden skin.
Allow the pudding to rest for about 10 minutes before serving.