Mont Blanc tart

Roll out the pastry with a little flour and line a 22-23cm round shallow tart tin. Leave the excess pastry hanging over the edge, prick the base with a fork and chill for 30 minutes.

Heat the oven to 190C/fan 170C/gas 5. Line the pastry case with some crumpled greaseproof paper, fill with baking beans and bake for 15 minutes, then remove the beans and paper and bake for another 5 minutes until the base looks dry and golden. Leave to cool, then cut the excess pastry off with a serrated knife.

Turn the oven down to 140C/fan 120C/gas 1. Mix 60g of the icing sugar with the flour. Whisk the egg whites until they reach soft peaks, then whisk in the caster sugar a spoon at a time, continually whisking, until the mixture is glossy and holds stiff peaks. Fold in the icing sugar mixture and spoon the meringue into a piping bag with a plain 1cm nozzle. Pipe little meringues of varying sizes onto a lined baking tray and cook for 1 hour, or until the meringues are hard. Open the door a couple of times to let out any moisture, or leave a wooden spoon in the door to leave it open a fraction. Leave to cool.

For the filling, beat the chestnut purée until it’s soft. Whip the cream until it just reaches soft peaks, then beat in the remaining icing sugar and fold this into the chestnut along with the rum (if using). Spoon into a piping bag, fitted with a star nozzle and chill for 15 minutes. Pipe the cream into the tart case in stripes. Pipe any remaining mixture onto the top in blobs. Dot some meringues among the blobs along with some pieces of marrons glacé. Dust the top with icing sugar.