Crostate also known as "open faced sandwich"are a traditional Italian sweet treat, most often filled with jam, preserved or fresh fruit, or nut-based fillings such as almond or hazelnut paste, or they can be filled with pastry cream, citrus curd or numerous other delights.
Put all the berries,lemon juice and sugar together in a heavy-based saucepan and heat over medium-low heat,stirring constantly.
When the berries have released their juices let it boil for a few minutes.
Add pectin and cook for another 4-5 minutes till it thickens .
Allow mixture to cool to room temperature.
Using an electric hand mixer or whisk, cream the butter and sugar until pale and fluffy for about 3-4 minutes. Add the egg, vanilla and lemon zest, one at a time, mixing thoroughly after each addition.
Add the flour and salt and mix until the dough comes together but remains soft, about 1 minute. Don't over-mix.
Wrap dough in plastic wrap and refrigerate for 30 minutes to one hour.
Lightly grease a shallow 9" metal pie dish.
On either a piece of parchment or a lightly floured surface, roll 2/3 of the dough out to a circle to generously line the pie dish.
Transfer the dough to the pie dish, press in gently and roll the edges to form a good surface for attaching the lattice later. Prick all over the bottom with a fork. Refrigerate the dough-lined pie dish for 30 minutes to reduce shrinkage during baking.
Preheat oven to moderate 180°C.
Line pastry with parchment and fill with dry beans . Bake until set, around 15
minutes.Remove the weights and parchment and allow to cool.
Preheat oven to moderately hot 200°C.
Roll the remaining dough to fit the pie dish and cut it into roughly half inch-wide strips.Spread the filling over the par-baked crust.
Arrange the strips of dough in a lattice over the filling trim as
needed and lightly pinch the ends onto the rolled edge of the bottom crust.
Place pie dish on a baking sheet and place in center of oven. Bake until lattice is golden,around 20 minutes. Meanwhile, prepare the glaze.
Heat the jam and water in a small saucepan over medium heat until mixture comes to a boil.
While glaze and pie are both still warm, brush over lattice crust.