Gather your ingredients so that you have everything close at hand on the counter or table.
Using a cutting board, slice lemons in half. With a citrus squeezer, squeeze the lemon juice into a glass measuring cup or bowl.
In a medium saucepan, mix together the large eggs and granulated sugar until combined. Stir in the freshly squeezed lemon juice, melted butter and lemon zest. Cook over medium-low heat for 3-5 minutes until thickened and reaches 160 degrees.
Allow to cool. If desired, you may strain the curd with a fine mesh strainer into a container. Cover and refrigerate until ready to use. Makes 1 2/3 cups.
Notes
*Unless otherwise indicated, all butter on this recipe site is salted.