London Lemon Curd

Directions

1. 1
   Combine sugar, lemon zest and eggs in a small saucepan over medium heat.
2. 2
   Stirring with a whisk, cook until sugar dissolves and mixture is light in color (about 3 minutes).
3. 3
   Stir in lemon juice and butter.
4. 4
   Cook for 5 minutes more, stirring constantly until the mixture thinly coats the back of a spoon.
5. 5
   Let cool, cover and chill.
6. 6
   The mixture will thicken as it cools.
7. 7
   If using in a cake, it is best to make this the day before.