In a microwave-proof bowl or jug whisk together the egg yolks and cornflour, then add the sugar and whisk this in as well.
Once the eggs and sugar are well-combined whisk in the lemon juice, lemon zest and melted butter.
Microwave on high power for one-minute intervals, stirring after each minute. Continue until the lemon butter has thickend to the point that it will coat the back of a metal spoon.
Allow to cool, then store in a clean jar in the fridge for up to 2 weeks.
Enjoy
Notes
Egg yolks: Although the recipe does work with whole eggs you will get a richer lemon curd if you use only egg yolks.
This is a quick lemon curd recipe, it is not designed to last for long periods as a preserve. It can be frozen for up to 3 months.
Egg yolk: The recipe will work with 2 whole eggs rather than 4 yolks.
Cornflour: Cornflour is known as corn starch in some parts of the world
Sugar: white granulated sugar or caster sugar will work.
Butter: This recipe will work with full-fat margarine or vegan butter if you need a dairy-free alternative.