in a large mixing bowl, sift together the flour and salt.
cut in the butter with two knives (or a pastry cutter) until the butter pieces are about the size of large peas.
whisk the egg and sour cream together until completely combined... gradually add it to the flour mixture. gently mix with your hands just until the dough begins to come together. (Note: Work the dough as little as possible or it will become tough.)
turn the dough out onto a floured work surface (or silacone mat). flatten the dough into one disk and one rectangle for lattice-topped pies or two disks for regular pies. Sprinkle it with a little flour and wrap well with plastic wrap; chill in the refrigerator until firm but malleable, about 1 hour, before rolling out. (Note: This will relax the dough and prevent butter from melting when handled.)
for the lemon curd: Whisk together the eggs, sugar, lemon juice and half of the zest in a large metal bowl.
place the bowl over a pan of simmering water and cook, stirring frquently, until very thick, about 20 to 25 minutes. (you may use a double boiler if you prefer.)
add the butter, one piece at a time, stirring constantly, until the butter is incorporated.
strain through a coarse strainer into a bowl, and then stir in remaining zest. cool completely, then cover with plastic wrap and place in the refrigerator until needed.
for the fruit... In a small sauce pan, mix the preserves and water over low heat until melted. half of the glaze will be spread on the bottom of the tart shell, and half will be used to glaze the fruit.
spread 1 cup of the Lemon Curd over the bottom of the prepared, fully baked pie shell... arrange the fruit in an attractive pattern on top. lightly brush the remaining melted preserves over the fruit, and serve immediately.