- 1/4 cup sugar
- 1 large egg
- 1/3 cup lemon juice
- 4 Tbsp butter
- Whisk the sugar, egg, and lemon juice together in a small sauce pot until smooth (remember to avoid aluminum materials as they will react with the acid in the lemon juice).
- Continue whisking while placing the pot over medium heat until it starts to thicken to the point it would cover a spoon.
- Remove the pot from the heat. Whisk in one tablespoon of butter at a time whisking until fully integrated before adding the next.
- Transfer the curd to an air-tight container and refrigerate until completely cooled and fully thickened.