Preheat oven to 200 degrees. Line 2 cookie sheets with parchment paper.
In a large glass or metal mixing bowl, beat egg whites, salt, and cream of tartar to soft peaks. Gradually add sugar, continuing to beat until stiff peaks form.
Gently fold in 1 tablespoon of the crushed peppermint. Drop by spoonfuls or pipe onto prepared cookies sheets, about 1 inch apart.
Sprinkle remaining crushed peppermint over the cookies. Bake for 1 approximately 1 1/2 hours–baking time will vary slightly depending on the size of your meringues. Do not allow meringues to brown. They should be completely dry on the inside.
When meringues are done, turn off the oven an leave the door ajar. Let meringues sit in the oven until completely cool. Loosen from parchment with a spatula.
Meringues may be stored, loosely covered, in a cool dry place for up to 2 months.