1 1-pound box confectioners' sugar
1 tablespoon shortening
2 tablespoons plus 1 teaspoon water
1 tablespoon light corn syrup
1 teaspoon fresh lemon juice
3/4 teaspoon peppermint extract
10 ounces semisweet or bittersweet chocolate chips
6 Starlight mints, unwrapped and crushed in a Ziploc with a rolling pin (optional)
Sift the confectioners' sugar into the bowl of a standing electric mixer and beat in the shortening on medium speed. In a small bowl stir together the water, corn syrup, lemon juice, and extract, then beat it into the sugar mixture until combined.
Knead the mixture into a ball (it will be very stiff), then use the bottom of a glass pie plate and firm, even pressure to flatten the ball between sheets of wax paper into a 9-inch disk that's about 1/4 inch thick (if you try doing this with a rolling pin, you will be much more frustrated, I assure you). Place the disk (with the wax paper) on a cookie sheet and freeze until firm, around 15 minutes.
Place the frozen disk on a cutting surface, remove and reserve the wax paper, and cover the cookie sheet with parchment. Use a 1-inch round cutter to cut out patties, moving them to the parchment as they're cut. Gather the scraps into a ball, use the pie plate and wax paper to flatten it again, and cut more rounds until all of the filling is used. Freeze the rounds for 10 minutes.
Meanwhile, melt the chocolate in the top of a double boiler over barely simmering water. Coat the patties one at a time, balancing each on a fork and dipping (use another fork as needed to flip the patty in the chocolate), then shaking excess chocolate and scraping the bottom of the fork against the edge of the bowl before returning the coated patty to the parchment. Make a ridged pattern one each patty by pressing a fork into the chocolate and lifting it straight up. Reheat the chocolate as necessary until all the patties are coated, then allow them to sit until set, about 1 hour.
