Half-fill your sink with cold water and have a large, clean bowl ready. Place milk in a wide pot. Split the vanilla beans down the middle, scrape their seeds into the milk and include the beans. Gently bring milk almost to the boil and remove from heat. Infuse for 10 minutes.

In a bowl, whisk the sugar and yolks until pale and frothy then pour in the hot milk and vanilla beans while whisking. Once combined, pour the contents back into the pot and place over a medium heat. Use a wooden spoon and stir gently and constantly in a figure eight - and don't leave. It takes about 8-10 minutes over medium heat to thicken. Hold the wooden spoon vertically and run your finger through the custard. If the line runs, it's not quite ready, but if the line holds, it is. Or taste the custard - if the yolks still have an eggy taste, it's not quite ready.*

Pour the custard into the clean bowl then place in the sink of cold water to stop from further cooking.

Serve warm or keep in the fridge until ready to serve.

*If tiny specks form, it means the cream and eggs are splitting – try pouring the custard into the bowl and whisking over the cold water to cool it quickly.