Mulled wine snowdrift meringue pie

Method

1. For the pastry, put the flour and butter in a food processor, then pulse until the mixture resembles breadcrumbs (or rub together in a mixing bowl with
   your fingertips). Pulse in the caster sugar with a pinch of salt. Add the egg and pulse to bring together in a dough (by hand, mix in using a wooden spoon), adding a bit of ice-cold water if needed. Transfer to a lightly floured surface, knead briefly and shape into a disc. Wrap and chill for 30 minutes.
2. Heat the oven to 200°C/180°C fan/gas 6 with a baking sheet inside to heat up. Roll the chilled pastry out on a lightly floured surface to the thickness of a pound coin. Use it to line the tart tin. Prick the base with a fork and trim the edge. Gently press the pastry into the fluted sides so it rises above the edge of the tin slightly (this will help counteract any shrinkage while baking). Chill for 15 minutes or freeze for 10 minutes.
3. Line the chilled pastry case with foil or baking paper, fill with baking beans or rice, then blind-bake on the hot baking sheet for 20 minutes. Remove the beans/rice and foil/baking paper, then return to the oven for 8-10 minutes until evenly sandy-coloured. Set aside to cool.
4. While the pastry is baking, make the filling. Toast the whole spices for a minute or two in a large heavy-based pan over a medium heat. Remove the pan from the heat, then add 200g of the sugar, the cornflour, orange zest and nutmeg and stir to combine. Gradually stir in the orange juice, cranberry juice and wine, mixing with a rubber spatula until smooth, then put back over a medium heat to bring back to a simmer. Cook for 5 minutes until the mixture is thick enough to coat a spoon.
5. Remove the pan from the heat and gradually add the butter, stirring, until melted and combined. Mix in the egg yolks (reserve the whites for the meringue), then return the mixture to the heat, stirring constantly, for about 10 minutes until it’s thick enough to briefly hold a channel in the mixture when you drag a spoon through it. Pass the curd through a sieve into the pastry case (discard the whole spices), then smooth the surface. Cover the surface directly with a baking paper, set aside to cool, then chill for at least 1 hour in the fridge.
6. For the meringue topping, put the egg whites in the bowl of a stand mixer fitted with a whisk attachment (but don’t turn it on yet). Put the remaining 300g sugar, vinegar and 3 tbsp water in a heavy-based pan over a low heat. Stir to dissolve the sugar, then remove the spoon. Bring to the boil and cook, swirling the pan regularly, until the syrup reads 112ºC on a thermometer. As soon as it reaches 112ºC, turn on the stand mixer and whisk the egg whites to medium-stiff peaks. By the time this happens, the syrup should have reached 120°C. With the whisk still running, carefully pour the syrup into the egg whites in a steady, thin stream, avoiding the whisk. Continue to whisk until the meringue is thick, glossy and completely cooled (about 10 minutes).
7. Gently spoon some of the meringue on top of the curd and spread it flat with a palette knife to seal the tart. Spoon the rest of the meringue on top, shaping it into a dome with peaks and swirls on top. Caramelise the outside of the meringue mountain with a blowtorch. Set aside at room temperature for at least 1 hour to firm up before serving.