Soften butter slightly, but do not allow to become oily.
Stir in sugar, salt, nutmeg and egg yolk using a wooden spoon.
Add flour, a little at a time, until mixture is too stiff to work with spoon.
Turn onto floured board and knead lightly, drawing in flour all the time until dough just begins to crack.
Roll out dough 1/4" thick and cut into desired shapes with cookie cutter: place on an ungreased cookie sheet.
Bake at 350F for 10 minutes or until delicately brown.
If desired, decorate cookies with strips of red or green maraschino cherries before baking.