2 medium Bramley apples, peeled, cored and chopped
½ tsp ground cinnamon
1 tbsp butter
1 British Gala apple, peeled, cored and cut into 1cm dice
320g pack puff pastry
2 tbsp milk to glaze
2 tsp demerara sugar
Put the Bramley apple, sugar, and cinnamon into a small pan with 1 tbsp water. Cover with a lid and simmer over low heat for 10-15 mins until the apple breaks down and turns into a compote.
Stir in the butter and the Gala apple and cook for a further 5 mins, uncovered, until the Gala apple is just soft but retaining its shape, and any excess water has evaporated to make a thick compote around the Gala chunks. Remove from the heat and leave to cool.
Heat the oven to 220C/200C fan/gas 7. Unravel the puff pastry sheet out on a work surface, and cut it into 4 even rectangles. Divide the apple filling to one side of each of the puff pastry rectangles, leaving a 1cm border. Brush the border with milk and fold over the empty side of the pastry over the filling and crimp together. Brush with milk and sprinkle with sugar. Make a small steam hole in the middle of each turnover.
Transfer to a lined baking sheet and bake for 20-25 mins until golden and puffed up.
Leave to cool for 10 minutes on a wired rack.