Place the vanilla pod, milk and cream in a pan and bring to the boil. Separate the egg yolks from the whites. Whisk together the sugar and the egg yolks. Pour the hot liquid over the egg yolks, stirring all the time. Return to the pan and cook for 2-3 minutes until you have a thick creme anglaise.
Place in a bowl, cover with cling film, and chill until needed.
For the coulis: Place the defrosted berry mix and the caster sugar in a pan, and bring up to a gentle simmer. Leave to simmer for about 15 minutes, or until most of the juices have evaporated. Blend the coulis if it is very chunky.
Set aside until cooled
Wash the berries, and remove from the stalks.
Spoon some coulis into each tart case, and pile the fruits generously. Set aside until ready to serve.
To serve: Spoon the custard over the tarts and serve immediately.
«Use any berries that in season. The coulis can be replaced with a good quality jam or preserve. If you prefer to serve a traditional version of this dessert, omit the tart cases, and serve in a shot glass.»