In a food processer, blitz together the butter, flour, sugar, almonds and yolk. Once combined turn the mixer off. Tip out and form a disk.
Cover with cling film then place the pastry in the fridge to rest for 15 minutes.
Preheat the oven to 200°C. Roll out the pastry until 2-3mm thick then use to line six loose bottomed tartlet cases. Trim off any excess. Place in the fridge for a further 10 minutes to cool.
Once rested for a second time, prick the base of each tart with a fork then place in the oven to cook for 8-10 minutes or until golden and cooked through. Set aside to cool.
In a saucepan bring the cream and the milk to the boil with the vanilla pod.
In a bowl whisk the eggs and sugar together. Pour the boiling cream mixture over the sweetened eggs whisking all the time before returning to the pan. Return to a medium low heat and whisk until thickened and coating the back of a spoon.
Strain then pour into each tart case filling up to the top. Place in the fridge to set for at least an hour.
Before serving, sprinkle the top of each tart with a little Demerara sugar making sure all the tart is covered evenly. Use a blow torch to caramelise the tops. Serve immediately.