Preheat the oven to 225°F. Line two baking sheets with parchment paper.
In a clean, dry bowl, beat the egg whites, cream of tartar and salt on medium speed until foamy, about 1 minute. With the mixer running, add the sugar 1 tablespoon at a time, then raise the speed to high and beat until stiff, glossy peaks form, 5 to 7 minutes. Beat in the peppermint extract.
Pipe or spoon 1½-inch mounds onto the baking sheets, about 1 inch apart.
Bake for 60 minutes, until the meringues are dry to the touch. Turn off the oven and leave them inside for 1 hour to cool and crisp.
Melt the chocolate and dip the bottoms of the cooled meringues, or drizzle it over the tops. Let set at room temperature for 15 minutes.
