In a large bowl stir together sugar and cornstarch. Stir in nectar or juice. Add pear slices; toss to coat; set aside.
Meanwhile, in a large mixing bowl, stir together flour, rosemary, and salt. Cut in shortening until pieces are the size of small peas. Stir in shredded cheese. Sprinkle 1 tablespoon of water at a time over part of the mixture, gently toss with a fork. Push to the side of a bowl. Repeat until all the dough is moistened. Divide dough in half. Form each half into a ball.
Roll half of the dough into a 13-inch circle. Transfer into a 9- or 9-1/2-inch deep-dish pie plate. Spoon pear filling into pastry-lined pie plate.
Roll remaining dough into a 12-inch circle. Place pastry on filling; trim 1/2 inch beyond edge of plate. Fold pastry top under bottom pastry. Crimp edge. With a knife cut slits in the top of the pie to allow steam to escape.
Preheat oven to 375 degree F. To prevent overbrowning, cover edge of pie with foil. Place pie on baking sheet. Bake for 25 minutes. Remove foil. Bake for 25 to 35 minutes more or until top is golden brown and filling is bubbly. Cool on a wire rack. Makes 8 servings.