PASTRY: In a large bowl and using a rubber spatula, thoroughly mix the flour, 1/2 teaspoon granulated sugar, and the salt.

Working quickly to prevent softening, cut butter into 1/4-inch pieces. Add to dry ingredients. Using a pastry blender or 2 knives, chop the butter into pea-sized pieces. Add vegetable shortening and with quick swipes of the pastry blender, cut the shortening into large chunks and distribute throughout the bowl. Continue chopping with the pastry blender until the mixture resembles coarse crumbs with some pea-sized pieces.

Drizzle the ice water over the flour mixture and work with rubber spatula until the mixture forms a ball, adding more water if needed. Flatten dough and wrap tightly in plastic wrap. Refrigerate at least 30 minutes or for several hours.

Roll out the chilled pie crust and cut into 24 pieces. With fingers press the pieces of crust into the bottom and sides of ungreased tea-sized muffin pans.

FILLING: Preheat oven to 375ºF.

Divide figs equally between crust lined pans. In a bowl, mix sour cream, 3 tablespoons granulated sugar, the eggs, vanilla, and 1/3 cup chopped nuts.

Spoon mixture over figs, filling cups to the top. Top each with a walnut half. Bake in preheated oven for 15 to 20 minutes or until puffed and brown. Cool in the pan. When cooled, run a sharp knife around each tart to loosen and unmold. Sprinkle each with powdered sugar.