Citrus-Glazed Mackerel

• 2 lemons
• 60 g (2 oz) honey
• 60

Using a microplane grater, finely grate half the zest of one lemon, then juice both lemons. Place the honey and soy sauce in a small saucepan and bring to the boil. Add the vinegar, lemon zest and 100 ml (3½ fl oz</