Step 1

Whisk together the lemon zest, juice and sugar in a heatproof bowl.

Step 2

Whisk in the eggs, and add the butter.

Step 3

Heat in the microwave in 30 second intervals, stirring between each burst.

Step 4

Cook for around 4-5 minutes, until the curd coats the back of a spoon.

Step 5

Pour through a fine sieve into a sterilised glass jar and leave to cool completely. It will thicken as it cools