White peaches and nectarines are more fragrant and more delectable than their yellow siblings. Unfortunately the yellow-fleshed fruit are the more robust travellers on the motorways from southern Europe to our chilly shores. Use whichever fresh peaches are available for this lovely summer tart.
Roll out the pastry to line the tart tin and bake blind in the preheated oven for 12–15 minutes until just starting to change colour. It may be more convenient to bake the pastry case a few days ahead to freeze until needed.
Spread the jam over the base of the pastry case. Cream the butter with the sugar until light and fluffy. Beat in the egg and stir in the ground hazelnuts and potato