1 medium-large very ripe banana (around 100g/3Β½oz peeled weight)
500g/1lb 2oz ripe strawberries, hulled, halved
1 vanilla pod, cut in half lengthways, seeds scraped out (or 2 tsp vanilla bean paste)
300ml/10fl oz double cream
6 large free-range egg yolks
300ml/10fl oz whole milk