Make the pastry case by sifting flour and salt into the mixing bowl of the stand mixer. Add cubes of butter and mix on slow with a paddle attachment until the mixture resembles fine breadcrumbs. Add the icing sugar and briefly mix.
Briefly whisk egg yolk and water in a small bowl before adding to the pastry mix. Mix on slow until the pastry forms. This shouldn’t take long at all, less than a minute – you don’t want to overwork the pastry.
Wrap the pastry in cling film and leave in the fridge for 30 minutes until firm but not hard.
Grease 1 x 23 cm ( 9 inch ) loose bottomed flan tin.
Roll out your pastry to about the thickness of a £1 coin ( ⅛ inch ) making sure the pastry circle is large enough for the diameter of your flan tin plus twice its depth.
Carefully line your tin with your pastry. Prick the bottom of the case with a fork and pop in the fridge for at least 15 minutes.
Preheat oven to 200℃ / 180℃ fan /400℉ / Gas Mark 6.
Line your pastry case with baking parchment and fill with ceramic beans, rice or dried beans and bake in the oven for 15 minutes.
Remove from the oven and carefully set aside the paper and beans. Pop the pastry case back in the oven for 5 minutes.
Leave to cool before preparing your fruit and making the frangipane.
Make your all in one frangipane by placing all the ingredients into a large mixing bowl and beating together for a couple of minutes.
Spread the frangipane into your pastry case and arrange the nectarine slices in concentric circles on the top of your frangipane, pressing them gently into the frangipane slightly.
Bake for 30 to 40 minutes until the frangipane is golden brown.
Brush with warmed and sieved apricot jam. Leave to cool before removing from the tin.