Steps
1. Melt the dark chocolate and margarine together in a microwave-safe bowl or over a double boiler until smooth.
2. In a separate bowl, whip the egg white until stiff peaks form.
3. In another bowl, mix the egg yolk with honey and milk until well combined.
4. Slowly fold the melted chocolate mixture into the egg yolk mixture.
5. Gently fold in the whipped egg white until no streaks remain.
6. Spoon the mousse into a small serving dish and refrigerate for at least 30 minutes before serving.