Add all the ingredients to a microwave-safe bowl and whisk really well until smooth
Pop it into the microwave for 1 minute, then remove and whisk again
Repeat the microwave and whisking process 3 to 4 times, whisking well each time, until the lemon curd is thick and custard-like
Pour it into a clean glass jar and let it cool slightly
Store it in the fridge for up to one week
