Star Anise is a spice most commonly used in Chinese and Vietnamese cooking. Star Anise (Illicium Verum) is a star shaped fruit from an Evergreen tree that is native to China. Use in stir-fries or with pork, veal or duck. Don't confuse star anise with the more common anise seed. While both impart a licorice flavor they are entirely different plants.
You may find this spice in a well-stocked grocery store. You can also be purchased readily online including at Amazon.com
Typically the whole star or segments can be added to the cooking pot. Your recipe may suggest grinding first in a mortar and pestle so just use as instructed.
In a sturdy mortar and pestle, grind the whole star anise pods until fine. Alternately you can use an electric coffee/spice grinder to finely grind star anise.
In a 1- to 1 1/2-quart heavy saucepan bring anise, sugar, butter, and vinegar to a boil over moderate heat, stirring, and boil 1 minute. Remove pan from heat and stir in flour and a pinch salt until mixture is smooth. Cool dough to room temperature. Form and bake cookies as directed at below.
Roll level 1/2-teaspoons dough into balls and arrange 4 inches apart on baking sheets. Bake cookies in batches in upper and lower thirds of oven, switching position of sheets halfway through baking, 10 minutes, or until cookies are flat and golden. Transfer parchment with cookies to racks to cool.
Cool baking sheets and line with fresh parchment between batches.