Line a baking sheet with waxed paper, ensuring the surface is fully covered for easy removal of the finished patties.

In a large mixing bowl, combine the sweetened condensed milk and peppermint extract. Gradually incorporate the confectioners’ sugar, adding it a small amount at a time. Continue mixing until a stiff, moldable dough forms and no longer adheres to your hands.

Roll the dough into 1-inch balls and place them onto the prepared waxed paper. Gently flatten each ball with your fingers to form round patties. Allow the patties to dry at room temperature for approximately two hours, turning them once halfway through the drying period.

In a medium saucepan set over low heat, combine the semisweet chocolate chips and shortening. Stir continuously until the chocolate is fully melted and the mixture is smooth. Remove from heat.

Using a fork, submerge each peppermint patty into the melted chocolate. Tap the fork lightly on the side of the pan to remove excess chocolate. Transfer the coated patties back onto the waxed paper.

Place the tray of dipped patties into the refrigerator and chill until the chocolate has fully set. Once firm, the patties are ready to serve or store.