1) Pre heat the oven to 120 degrees C.
2) In a large pan pour the milk, cream, crush the whole nutmeg and add this too.
3) Cling film the top of the pan and bring to a simmer gently on a low heat then place to one side to infuse. The cling film helps the infusion.
4) In a mixing bowl add the yolks and castor sugar whisk together, gently pour the infusion over the eggs and sugar and mix well.
5) Pass the custard through a sieve to remove all of the nutmeg, into an oven proof dish that will hold all the mix (roughly 600ml) making sure the dish is filled right to the top. Place this in a deep oven tray that will allow you to poor 2cm of warm water in the bottom. Bake in the oven for 30-45 min.
6) Once the set custard is cooked allow to cool( at this stage it keep in the fridge for 2 days before serving) sprinkle over a layer of castor sugar and caramelise with a blow torch or under the grill. Serve immediately.