(There are a variety of "authentic" shortbread recipes. This one, shared by a true Scot, has always worked well for the author.)
2 c. all-purpose flour
2 1/2 T. cornstarch
3/4 c. confectioners' sugar
1 c. real butter, room temperature
Mix all ingredients by hand just until no longer crumbly. Roll into a flat circle and score like a pie, or cut into rounds with a cookie cutter. Make holes with a fork over the entire surface. Bake at 350 degrees until just firm, about 15 minutes. Do not brown.
From the July 1992 issue.