Split the vanilla bean, scrape the seeds and put both the bean and the seeds in a pot with milk
Add vanilla sugar, bring to boil and take off the fire to rest about 10 minutes to infuse the flavour
Beat the egg yolks and sugar until pale and creamy
Take the vanilla bean out of the milk and pour the milk into the egg mixture stirring continuously
Return the mixture into the pan and stir constantly on low heat until the custard thickens. DO NOT LET IT BOIL or the custard will curd and separate!
Let the custard cool down, then transfer into a glass bowl and chill in the fridge for at least 3-4 hours or overnight
Whip the cream and carefully mix with the chilled custard
Pour into the ice cream maker and freeze according to the instruction specific to the manufacturer's instructions.
Transfer to a freezer safe container and keep up to a month - if it doesn't disappear that same day!
Notes
If the flavour is too rich, use two whole eggs instead of four egg yolks or omit eggs all together and thicken the milk with little corn flour Don't throw the vanilla bean after cooking: let it dry and store in a glass jar with caster sugar (very fine crystal sugar) - this is how I make my own very aromatic vanilla sugar!