For the dough:
For the filling:
1. Prepare the dough. In a bowl mix the flour, sugar and salt. With a pastry blender or 2 knives, cut in butter until mixture resembles coarse crumbs. Sprinkle cold water and mix with a fork to form a firm dough (do not use fingers).
2. Roll out the dough and cut according to sizes of the pans (consider the borders); line the molds with the dough. Cut and even the borders. Prick with a fork, place a wax paper on the bottom and fill with some weight (beans, rice, etc.). Bake in a 400°oven for 10 minutes; remove the weight and wax paper and bake until golden. Let cool.
3. Place the grapes in each tart. Bake for 12 - 15 minutes longer. Let cool.
4. In a small saucepan heat the preserve to melt. Remove from heat and add sherry. Brush the grapes with the melted preserve. Let cool and serve with whipped cream.