Pastry: Preheat oven to 375 degrees F. In a large bowl stir together flour and salt. Using a pastry blender, cut in shortening and butter until pieces are pea size.
Sprinkle 1 tablespoon of the water over part of the flour mixture; toss with a fork. Push moistened pastry to side of bowl. Repeat moistening flour mixture, 1 tablespoon of water at a time, until flour mixture is moistened. Gather flour mixture into a ball, kneading gently until it holds together. Divide pastry in half; form halves into balls.
On a lightly floured surface use your hands to slightly flatten one pastry ball. Roll it from center to edges into a circle 12 inches in diameter.
Fold the pastry into quarters. Unfold pastry into a 9-inch pie plate. Ease pastry into plate without stretching it. Trim pastry 1/2-inch beyond pie plate rim.
Roll remaining ball into a 12-inch-diameter circle. With a fluted or straight edge pastry wheel, cut 3/4-inch wide strips; cover and set aside.
Filling: In a very large bowl, combine granulated sugar, tapioca, and lemon zest. Add cherries and almond extract; gently toss until coated. Transfer to the pastry-lined pie plate.
Lay half of the pastry strips on top of the filling about 3/4-inch apart. Fold alternating pastry strips back halfway. Place a strip in the center of the pie across the strips already in place. Unfold the folded strips. Place another strip across the first set of strips parallel to the strip in the center. Repeat until lattice covers filling. Trim any excess dough from the strips. Press strip ends into bottom pastry rim. Fold bottom pastry over strip ends; seal and crimp edge.
In a small bowl beat together egg and water. Brush top pastry with egg mixture and sprinkle with coarse sugar. To prevent overbrowning, cover edge of pie with foil. Place a foil-lined baking sheet on the rack below the pie in the oven. Bake pie 45 minutes. Remove foil. Bake for 45 minutes more or until fruit is tender and filling is bubbly in the center of the pie. Cool on a wire rack.
Topping: In a medium bowl combine whipping cream, sour cream, 2 tablespoons granulated sugar and vanilla. Beat with an electric mixer on medium to high speed until soft peaks form. Pipe whipped cream atop each serving. Sprinkle with almonds.
