Martha Collison's lime & chocolate macaroons

1. Preheat the oven to 180°C, gas mark 4 and line a large baking sheet with baking parchment.

2. Mix the desiccated coconut, condensed milk, half the lime zest and all of the lime juice in a bowl until it forms a thick paste. Set aside.

3. Place the egg white and a pinch of salt into a small bowl, and beat using an electric whisk until stiff peaks form. Add the caster sugar, 1 tbsp at a time, and beat again to form a glossy meringue.

4. Fold the meringue mixture into the coconut mixture until the 2 are evenly mixed.

5. Using 2 spoons, form heaped spoonfuls of the mixture. Place 12 of these in mounds on the prepared baking sheet, spacing them a few centimetres apart. Bake for 15-18 minutes, until the tops of the macaroons are starting to brown. Allow to cool briefly on the baking sheet before transferring to a wire rack to cool completely.

6. Drizzle the cooled macaroons with melted dark chocolate using a piping bag or the prongs of a fork, then sprinkle with the remaining lime zest before allowing to set. These macaroons will keep for 4-5 days in an airtight container.