Line a large baking sheet with foil; set aside. For crust: In a medium bowl, stir together the 1-1/4 cups flour, the 1-1/2 teaspoons lemon peel, the salt, and the 1/4 teaspoon mace. Using a pastry blender, cut in the shortening until pieces are pea-size. Sprinkle 1 tablespoon of the ice water over part of the flour mixture; gently toss with a fork. Push moistened dough to the side of the bowl. Repeat moistening flour mixture, using 1 tablespoon of the remaining ice water at a time, until all the flour mixture is moistened. Form dough into a ball. On a lightly floured surface, use your hands to slightly flatten dough. Roll dough from center to edge into a circle about 13 inches in diameter. Transfer dough circle to prepared baking sheet.

Preheat oven to 375F. For filling, spread almonds on dough circle to within 2 inches of the edge. Place pears in a large bowl. In a small bowl, combine the 1/2 cup sugar, the 4 teaspoons flour, the 2 teaspoons lemon peel, and the 1/2 teaspoon mace. Toss half of the sugar mixture with pears. Mound pear mixture on top of the almond-covered dough. Sprinkle remaining sugar mixture over pear mixture. Dot with butter.

Fold dough edge up and over pears, pleating dough gently as needed. In a small bowl, combine egg white and the 1 tablespoon water; beat with a fork. Brush mixture onto the top and side of the dough. Sprinkle with additional sugar.

Bake about 45 minutes or until filling is bubbly, pears are tender, and pastry is golden. If necessary to prevent overbrowning, cover edge with foil for the last 5 to 10 minutes of baking.

Cool on the baking sheet for 30 minutes. Serve warm. If desired, serve with Spiced Whipped Cream or ice cream. Makes 8 servings.

Spiced Whipped Cream: In a chilled small bowl, combine 1/2 cup whipping cream, 1 tablespoon sugar, and dash ground mace. Beat with the chilled beaters of an electric mixer on medium speed until soft peaks form (tips curl).