Directions

1. Put the butter into a small mixing bowl. Zest the limes into the bowl using a fine grater, such as a Microplane. Add the Magic Salt and beat with a spoon or small spatula until well combined. 

2. Juice half of one of the limes and add 1–2 teaspoons of the juice to the butter. Beat the juice into the butter until the juice is completely incorporated. Taste and add more lime juice and a pinch of sea salt, if you you like.

3. Pack the butter into a ramekin (or roll in waxed paper) and chill until firm.