6 small apples, cored, peeled and halved horizontally
400g block puff pastry
flour, for dusting
Preheat the oven to 200°C, gas mark 6. Put the sugar and 55ml water in a 24cm round ovenproof pan set over a medium heat. Simmer for 5-7 minutes until the sugar has dissolved and you have a syrupy, caramel consistency. Stir in the butter and 1 tbsp sea salt flakes. Add the apples cut-side up and cook for a further 5 minutes. Remove from the heat.
Place the dough on a lightly floured surface and roll out to a 0.5cm thickness. Cover the apples with the pastry, pushing the edges down and pricking all over with a fork.
Cook for 25-30 minutes until the pastry is well risen and golden brown. Leave to rest for 10 minutes. Carefully tip the juices from the pan into a heatproof bowl, then invert the tart onto a plate. Spoon the caramel juices over and sprinkle with a little extra sea salt. Serve warm.