2.5cm/1in piece root ginger, peeled and chopped
50g/2oz rhubarb, chopped
50g/2oz plain flour
pinch arrowroot
3 tbsp soft brown sugar
2 tbsp caster sugar
4 tbsp caster sugar
1 tsp vanilla essence
1 vanilla pod, seeds scraped out
25g/1oz butter
25g/1oz cold butter, chopped
3 free-range egg yolks
500ml/17fl oz milk