Soak the vanilla pod in the warm milk for 1 hour. Meanwhile place the gooseberries into a saucepan over a medium heat with half of the sugar and cook for 45 minutes until broken down and soft. Mash just a little to help release flavour. Remove from the heat and allow to cool.
Strain the vanilla milk into a saucepan and discard the vanilla pod. Bring to a simmer and then immediately remove from the heat. Whisk the egg yolks, flour and remaining sugar in a bowl then add to the warm milk, stirring constantly. Continue to stir until a thick custard forms. Remove from the heat and pour into a glass bowl. Cover with cling film and place in the fridge for 2 hours. Stir in the gooseberries and the whipped cream. Serve chilled.