Pastry Crust: In a food processor, place the flour, salt, and sugar and process
until combined. Add the butter and process until the mixture resembles coarse
meal (about 15 seconds). Pour 1/8 cup (30 ml) water in a slow, steady stream,
through the feed tube until the dough just holds together when pinched. Add
remaining water, if necessary. Do not process more than 30 seconds.
Turn the dough out onto your work surface and gather it into a ball. Cover with
plastic wrap, and refrigerate for about an one hour before using. This will
chill the butter and allow the gluten in the flour to relax.
While the pastry is chilling, line a baking sheet with parchment paper. Once the
pastry has chilled sufficiently, remove the pastry from the refrigerator and
divide into four equal portions. On a lightly floured surface, roll each portion
of pastry into a 7 inch (18 cm) circle. Place the four pastry circles onto the
prepared baking sheet and cover with plastic wrap. Place in the refrigerator to
firm up the pastry while you make the filling.
Filling: In a large bowl, combine the berries, sugar, lemon zest (if using), and
flour. Remove the pastry from the refrigerator and divide the filling between
the four pastry circles, leaving about a 1 inch (2.5 cm) border around the
outside edges of the pastry. Gently fold the edges of the pastry up and over the
filling, leaving the center of the tart open. Press the edges gently so the
pastry sticks together. Once all the tarts are assembled, cover and return to
the refrigerator for about 15 - 30 minutes to chill.
Meanwhile, preheat the oven to 400 degrees F (200 degrees C) and place rack in
center of oven. Remove the unbaked assembled tarts from the refrigerator and
bake for approximately 25 - 30 minutes or until the crust is golden brown and
the juices are bubbling and start to run out from the center of the tart. Remove
from oven and place on a wire rack to cool before serving. Serve with softly
whipped cream or vanilla ice cream. Cover and refrigerate any leftovers.