1. Place the chocolates and ½ cup boiling water in a medium saucepan. Whisk until smooth. Add the cocoa mix and continue whisking while adding the remaining boiling water in a steady stream. Whisk in the milk, then heat over medium heat until steaming hot but not boiling. Keep hot over low heat.
2. Whisk the cream just until soft peaks form. Whisk the creme de menthe into the cocoa, then divide among 8 mugs. Top with the cream and crushed mint candies and serve immediately.