Step 1 Place the gelatin, sugar and salt in a large bowl. Add the boiling water and stir until completely dissolved, at least 3 minutes. Stir in the cold water. Refrigerate until slightly thickened, about 10 minutes.
Step 2 Beat the whipping cream and peppermint extract with an electric mixer on medium speed until soft peaks form, 2 to 3 minutes. Gently stir the cream mixture into the chilled gelatin until well blended.
Step 3Pour into molds, dessert glasses or a large glass dessert bowl. Refrigerate until set, 3 hours. Garnish with chocolate shavings, if desired.