Step 1

Add the eggs, egg yolks, lemon zest, lemon juice, sugar, and cornstarch in a large bowl. Whisk together until well combined and cornstarch is fully dissolved.

Step 2

Pour into a medium saucepan and cook over medium-low heat, stirring constantly with a wooden spoon, until thickened; about 7-10 minutes. You'll know it's ready when the curd coats the back of the spoon and is about the thickness of pudding.

Step 3

When the curd has thickened, immediately remove it from the heat and stir in the butter.

Step 4

Run the curd through a fine-mesh sieve to remove any bits of scrambled egg and transfer to a small bowl.

Step 5

Cover the bowl with plastic wrap making sure the wrap is touching the surface of the curd to prevent a skin from forming.

Step 6

Refrigerate for at least 2 hours or until set before serving.