Finely grate the rind of the lemons and remove the juice. Lemons vary in size and you need about a cup (250ml) juice for this recipe.

Place lemon juice, lemon rind, sugar and butter in the top half of a double boiler or in a heatproof bowl set over a pan of simmering water. Stir with a wooden spoon until butter melts. Add the beaten eggs and continue to cook, stirring constantly, until mixture thickens to the point where it coats the back of the spoon.

Heat clean jars (remove lids first) in microwave on High for 2 minutes. Pour the hot lemon curd into the hot sterilised jars and seal immediately with lids. Keeps for a month in the fridge or several months in the freezer.