Lightly oil a baking sheet, or line with baking parchment. Tip the sugar into a heavy-based frying pan set over a medium-low heat, and cook until dissolved and lightly golden. Don’t stir – tilt the pan for an even colour.

Add the walnuts, rosemary, 1 tsp sea salt flakes and 1/2 tsp freshly ground black pepper, and stir briefly. Carefully pour the mixture onto the prepared sheet. Use two lightly oiled teaspoons to separate the nuts if you prefer them packaged individually, but don’t touch them as they’ll be very hot. For a more rustic look, leave to cool, then roughly bash into chunks using a rolling pin. Pack into small containers or bags. Will keep for up to three weeks in a dry, cool place.