Whisk the egg and yolks together in a separate bowl to ensure they are fluffy and well incorporated together .
Place a double boiler or bowl over a pot of simmering water on the stove.
Add the lemon juice and the sugar and stir with a spatula until sugar has dissolved
Pour the lemon sugar mix over the whisked eggs and whisk vigorously to ensure the eggs don't scramble. The best technique is to drizzle and whisk simultaneously.
Pour mixture back into double boiler and continue to stir for 5 -10 minutes. This all depends on how much heat your mixture is exposed to, which also depends of the size of the surface area of your double boiler. The mixture will thicken. I never leave the pot! Once the mixture is thick, taste. There must be no eggy taste. This is the biggest mistake made when making sauces, curds and homemade ice-cream. There is nothing worse than eggy tasting ice-creams, curds and sauces. Remove the pot from the double boiler and whisk in the butter until melted and smooth. Taste!Taste again! to make sure it's good and then again just in case you are not yet convinced this is the best lemon curd you have ever tasted. This recipe suits my taste. So many of the ones I've tried and tested had too much sugar, or too much butter or the egg ratio's weren't balanced. The time to add the butter was also important in getting the flavour balanced perfectly for me.
