In small microwavable bowl, microwave remaining 3/4 cup chocolate chips and the shortening uncovered on High 30 to 45 seconds, stirring once, until softened and chips can be stirred smooth. Spoon into resealable food-storage plastic bag; seal bag. Cut tiny tip from 1 bottom corner of bag; drizzle chocolate over bars. Refrigerate about 1 hour or until chocolate is firm. For bars, cut into 8 rows by 6 rows. Store covered in refrigerator.