This classic pie is normally made with ground almonds but this works great with the pistachios. Simple to make but looks super impressive.

Preheat the oven to 180C/160cfan/Gas 4. Line a large baking tray with non stick baking parchment. Prepare the pistachio filling. Place the pistachios in a food processor and blitz until you have a finely ground mixture.

Place the butter and sugar together in a large bowl and mix together until you have a pale and fluffy mixture. You can use a wooden spoon or electric hand whisk for this. Beat in the egg and then stir in the flour, pistachios and lemon zest until you have a thick paste.

Cut the puff pastry into two making sure one piece is slightly bigger than the other. Dust a work surface with flour and roll out the smaller piece of pastry to a 20cm round using a plate to cut around as a template. Roll out the larger piece to a round measuring 23cm.

Place the smaller 20cm round on the baking tray and then spread with the pistachio paste making sure you leave a 2cm edge all the way round the pastry.

Place the raspberries in a bowl and add a teaspoon of icing sugar. Mash the berries gently with the icing sugar and then pile on top of the pistachio paste.

Brush the edge of the pastry with a little egg and then carefully place the other larger disc of pastry over the top of the filling, pressing down well. Pinch the pastry together to seal with your finger and thumb or the tines of a fork. Then using the blunt side of a small knife make semi circular arcs running from the centre of the pie to the edges, make sure you just score the pastry without cutting through it. Brush with beaten egg and place in the fridge to chill for at least 10 minutes.

Place in the oven and bake for 25 - 35minutes until golden and cooked on the top and bottom. Sieve the remaining icing sugar over the top and return to the oven for 3 minutes to glaze the top. Leave to stand for about 5 minutes before serving.