Place the milk and vanilla bean into a saucepan over low heat. Heat the milk until just below boiling. Leave to infuse for 20minutes.
Once infused, discard vanilla pod. Place back onto low heat and bring back to below boiling.
Meanwhile, in a bowl whisk the egg yolk and sugar until pale and combined.
Add a little of the hot milk to the egg mix and whisk to bring the eggs up to temperature.
Add the eggs into the milk mix and whisk over a low heat until the custard thickens and coats the back of a wooden spoon or reaches 84C (if you have a thermometer). Allow to cool to room temp.
In a blender liquidise the cherries until a puree is reached. Strain through a sieve.
Add the cherry puree to the custard and stir to combine. Chill for 4 hours or overnight.
Churn cold custard following your ice cream machine instructions. Adding the chocolate chips half way.
or
Place in a container in the freezer and using a hand mixer beat the custard for 5 minutes every hour for 5 hours. adding the chocolate chips after 2 hours.