Place white chocolate and shortening in 2-cup glass measure.
Microwave at HIGH (100% power) about 1 1/2 minutes or until melted, stirring after every 30 seconds of cooking.
Pour melted white chocolate onto back of baking sheet, marble slab or other heat-resistant flat surface.
Quickly spread chocolate into very thin layer with metal spatula.
Refrigerate about 10 minutes or until firm, but still pliable.
Using small straight-edge metal spatula or paring knife held at 45° angle, push spatula firmly along baking sheet, under chocolate, so chocolate curls as it is pushed.
Using small skewer or toothpick, transfer curls to waxed paper.
Store in cool, dry place until ready to use.