In a heavy saucepan, melt butter over medium heat.
While butter is melting, whisk together lemon juice and eggs.
Add sugar to butter and stir to incorporate.
Whisking vigorously, add lemon and egg mixture to the sugar mixture. Continue to stir over medium heat until the curd coats the back of a wooden spoon. Remove from heat.
Pour curd through a mesh strainer. Stir the zest into the curd and store in the refrigerator tightly covered.
Nutrition facts are sometimes provided below and are calculated using an online calculator. With specific brands of ingredients and additions, omissions, or substitutions the nutrition facts may change. We encourage you to use your own nutrition facts caculator to obtain the most accurate nutrition facts for your meal.