Place the strawberries, castor sugar and lemon juice in a saucepan.
Bring up to a boil and simmer on medium high for about 7 minutes.
Blitz with an emersion blender until smooth. Stir through the gin and set aside to cool.
To make the ice cream, pour the milk and cream into a saucepan. Add a quarter cup of sugar, vanilla pod and seeds.
Bring the mixture up to a simmer, stirring to dissolve the sugar. Remove from the heat and discard the pod.
Place the egg yolks and the remaining sugar in a bowl and whisk until pale and thick.
Slowly add the warm cream to the yolks before pouring the mixture back into the saucepan.
Cook over a medium heat, stirring all the while, until the cream is thick enough to coat the back of a spoon.
Strain the custard into a bowl and cool for 30 minutes. Cover with cling film and chill overnight.
Churn in an ice cream maker until firm.
Spoon half the ice cream into a container. Drizzle with a third of the strawberry coulis.
Repeat the layering once more then swirl through with a skewer.
Cover and freeze for several hours.
Serve with the remaining coulis on the side.