In a large mixing bowl, combine icing sugar, condensed milk, peppermint flavoring, and water. Mix until a stiff paste forms.

Adjust the mixture's consistency by adding icing sugar or water until no longer sticky.

Dust a clean surface and rolling pin with icing sugar, then roll the peppermint paste to 0.5 cm thick.

Use a round cutter to stamp out circles from the rolled mixture and place them on a parchment-lined tray.

Leave the rounds to dry at room temperature for about 30 minutes.

Melt dark chocolate in a heat-proof bowl over simmering water until smooth.

Coat the dried peppermint rounds with melted chocolate and let excess chocolate drip off.

Chill the tray in the refrigerator for about 10 minutes, or until chocolate is fully set.

Serve on a platter or store in an airtight container.