Dark chocolate has long had a “better for you” halo, and not without reason. Compared to milk chocolate, dark varieties contain more fibre, iron, magnesium and much-discussed polyphenols – plant compounds linked to heart health and reduced inflammation. While it’s hardly a substitute for a balanced diet, choosing a bar with at least 70 per cent cocoa does tilt things in a more virtuous direction, nutritionally speaking. The rich, fruity and earthy can be an acquired taste. But what starts as a slightly bitter square at 70 per cent can, over time, become genuinely enjoyable. And you may find yourself reaching for 85 or even 90 per cent bars – personally, I’ve found myself gradually nudging up the cocoa scale as I satisfy that post-dinner treat. That said, this habit doesn’t come cheap. With many branded bars creeping past the £3 mark, dark chocolate can quickly become one of those small luxuries that quietly inflate your weekly food shop.…