For Pastry Crust:
*2 1/2 cups flour
*1 teaspoon salt
*1 tablespoon white sugar
*1 cup unsalted butter, chilled, and cut into 1 inch pieces
*1/4 to 1/2 cup ice water
*Filling (see below)
2. Add the butter and process until the mixture resembles coarse meal (about 15 seconds).
3. Pour 1/4 cup (60 ml) water in a slow, steady stream, through the feed tube until the dough just holds together when pinched.
4. Add remaining water, if necessary. Do not process more than 30 seconds.
5. Turn the dough out onto your work surface and gather it into a ball.
6. Divide the dough into two equal pieces,flatten each portion into a disk, cover with plastic wrap, and refrigerate for 30 minutes to one hour before using. This will chill the butter and allow the gluten in the flour to relax.
*1 pound rhubarb cut into 1 inch pieces (approximately 3 cups)
*1 pound fresh strawberries, cut into 1 inch pieces
*1/4 - 1/3 cup flour
*3/4 - 1 cup white sugar
8. Once the pastry has chilled sufficiently, remove the two disks of pastry from the refrigerator and divide each disk into four equal portions (you will have eight portions altogether).
9. On a lightly floured surface, roll each portion of pastry into a 7 inch (18 cm) circle.
10. Place approximately 1/2 - 3/4 cup of filling in the center of each pastry circle, spreading the filling out to about 1 inch (2.54 cm) from the edge of pastry.
11. Gently fold the edges of the pastry circle 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.
12. Meanwhile, preheat the oven to 400 degrees F.