Combine the white sugar and eggs in a medium-sized saucepan and whisk together.
Combine the lemon juice and lemon zest and whisk until fully incorporated.
Put the saucepan on medium heat and gradually incorporate the butter, adding one tablespoon at a time and ensuring that each tablespoon melts before adding the next.
Whisk constantly while cooking for an additional 5 minutes after incorporating all the butter.
Take off the heat and let it cool down.
Place the lemon curd in the refrigerator and let it set for 2-3 hours.
Notes
Very Fresh Lemons: To achieve the best flavor, use fresh and juicy lemons. Their zest and juice will provide the brightest and most vibrant citrus taste.
Extra Flavor: For an extra burst of flavor, you can add a touch of vanilla extract or a splash of limoncello liqueur to your lemon curd recipe.
Strain for Smoothness: For an ultra-smooth texture, strain the lemon curd after it has cooled down. This will remove any bits of zest or cooked egg that may have formed during the cooking process.