Preheat the oven to 180ºC and line a baking tray with non stick baking paper.
Roll the pastry out onto the grease proof paper and top with the strawberry conserve leaving a 1 ½ inch border around the edge of the pastry, and set aside while you make the filling.
In a medium bowl mix the corn starch and the 1 teaspoon of water. Stir in the honey and set aside while you prep the strawberries.
To prep the strawberries, cut the green tops off and slice into half or quarters. Stir into the honey cornstarch mix. Stir well to coat all the strawberries in the honey.
Scatter the strawberries onto the pastry over the conserve being sure to maintain the border of the pastry.
Brush the edge of the pastry with the egg wash and fold the edges up over the strawberries. Brush the edge of the folded pastry with the egg wash and scatter with the demerara sugar. Bake in the preheated oven for about 30-35 minutes until the pastry is deep golden and crispy around the edges and the bottom.
Scatter with the chopped pistachios if using.
Serve warm with ice cream or at room temperature.