This is a classic Hotel Chocolat selector, it has been around for many years, surviving longer than all the non-standard chocolate selectors (70% dark, 85% dark, etc.) and there's good reason for that. The pack consists of two thin 50g bars of 70% dark infused with tiny mint crispy pieces and high quality peppermint oil. The taste makes it obvious of the quality of oil they use; the bar tastes better than any mint chocolate I have ever tasted – it tastes ‘real', if that makes sense – rather than the bland ‘fake' tastes you get from most mint chocolate.
You can tell ever since Green & Black's changed their mint dark chocolate from having a fondant centre to a solid bar, that they were trying to imitate this minislab, but they have fallen short of the mark, and have definitely lost this battle!
The pack costs £3.75, or £3.15 if you buy three or more mix and match selectors.
Buy them in store or at hotelchocolat.com