For the pastry, place the flour, almonds, butter and sugar in a food-processor with a pinch of salt. Process until it resembles breadcrumbs and add the egg, with a splash of cold water if necessary to bind. Process briefly, then bring the mixture together with your hands, wrap in clingfilm and chill for 1 hour.
Roll out the pastry to fit a shallow 23cm/9in tart tin. Prick the base all o