Heat oven to 325. In large bowl, beat powdered sugar and butter until light and fluffy. Add orange peel; blend well. Lightly spoon flour into measuring cup; level off. Stir in flour and cornstarch; mix well. Stir in 3/4 C chocolate chips. Divide dough into four parts. Shape each part into a smooth round ball.
On ungreased cookie sheets, press or roll each ball of dough into a 6-inch circle, 1/4-inch thick. With knife, score each into 8 wedges; leave wedges in place. Prick each wedge 3 times with fork.
Bake for 17 to 20 minutes or until edges are lightly browned. Cool 5 minutes; prick again with fork and cut into wedges. Remove from cookie sheets; cool completely.
In small saucepan over low heat, melt 1/2 cup chocolate chips and shortening, stirring constantly. Dip rounded end of cooled shortbread wedges in melted chocolate; place on waxed paper or cooling rack. Let stand until set.
2 Points Each; 102 for Entire Recipe