Combine nuts, flour and sugar in a large bowl. Stir in melted butter, vanilla and egg white. Mix together until evenly blended. Spread in an 11" (28 cm) tart pan with removable sides. Pat down with fingertips to pack mixture evenly on the bottom and sides of the pan. Refrigertate for 30 minutes.
Preheat oven to 350°F (180°C). Bake in the center of oven 20 minutes or until golden. Remove to wire rack and cool completly before filling.
Place currant jelly and water in small saucepan. Dissolve completely over low heat, stirring continually. Brush ¼ of the mixture over baked nut crust. Refrigerate. When firm, cover glazed pie crust with sliced berries. Arrange whole berries on top. Drizzle remaining glaze over top. (Heat glaze slightly if too firm.) Drizzle with strands of melted chocolate. Chill. Dust with icing sugar before serving. Makes 8 to 10 servings.