Combine sweetened condensed milk and peppermint extract. Beat in powdered sugar, a little at a time, to make a stiff dough that is not sticky. Form into 1 inch balls and put on waxed paper.  Chill for one hour.  Flatten with bottom of glass to form patties. Let patties dry at room temperature for one hour, flip them over, then let dry another hour.

Melt and temper chocolate.  Dip patties one at a time into chocolate with a fork.  Tap off the excess and let harden on wax paper.