Step 1

Preheat oven to 325°F. Beat butter and sugar in large bowl with electric mixer on high speed 3 minutes or until light and fluffy. Combine flour and cornstarch. Gradually add to butter mixture, beating until well blended. Stir in chocolate.

Step 2

Shape dough into ball, then divide into 3 equal pieces. Flatten 1 piece into 4-inch round on baking sheet. Score into 8 wedges with sharp knife. Repeat with remaining dough.

Step 3

Bake 30 minutes or until shortbread is set and lightly browned. Cool 5 minutes on baking sheet. Remove to wire racks; cool completely. Cut each round into 8 wedges to serve.