Mix the butter and sugar in a stand mixer until pale and creamy (use a paddle beater, otherwise mix by hand but use cold butter).Add salt then other ingredients until just mixed, then stop. Form the dough into a ball, wrap in cling film or in a bag and chill in the fridge for at least an hour.For more complete instructions, follow the recipe on pages 106-109 in my book, 'Teatime in Paris'.
Take the pastry out of the fridge. Roll out the pastry on a very lightly floured surface to 4mm thickness. Press into the pastry ring or pan. Roll over the rolling pin on top to trim then push the pastry again into the ring to ensure it's straight against the sides. Return it to the fridge for at least 30 minutes.Preheat the oven to 180°C/160°C fan/360°F/Gas4.
Blind bake the pastry by topping with parchment paper and fill with baking beans, washed coins, rice or dried beans. Bake in the oven for 15 minutes, then set aside to cool on a wire rack, removing the baking beans (this seems short but it will be baked again later with the apples).
Prepare a sheet of parchment paper on the side. Heat a large frying pan over high heat and add the butter. Meanwhile, chop the apples into large dice (cut them quickly and there's no need to use lemon juice). When the butter is golden, fry the apples in sugar and vanilla for at least 5 minutes until seared a golden brown on one side. Turn the apples, cooking on high still for another 2 minutes then transfer to the parchment to cool.
In a bowl, whisk the egg whites just with a fork until loosened up then stir in the sugar and sliced/chopped) nuts.
Evenly spread the cooled apples into the pastry base and top with the nougat. Bake in the oven for 25-30 minutes or until golden brown. Cool on a wire rack.
Best served on the day but can be kept refrigerated until next day. Also freezes well (double wrap). Serve with vanilla ice cream, a dollop of crème fraîche, chestnut ice cream or a warmed pot of salted caramel sauce.See more on types of apples for baking.Measures: Please note that all my recipes are best made using digital kitchen scales in precise metric grams. Both ounces (and cups) are given as an approximate guide.