1/4 c finely grated lemon rind
2/3 c freshly squeezed lemon juice
2 c sugar
1 c butter
4 eggs, slightly beaten
Combine first four ingredients in top of a double boiler. Cook over simmering water, stirring constantly, until butter melts. Gradually stir about 1/4 of hot mixture into eggs; then add egg mixture to remaining hot mixture, stirring constantly. Cook over simmering water, stirring constantly, until mixture thickens and coats a spoon (about 15 minutes). Remove from heat; cool. Refrigerate for up to 2 weeks in a tightly covered glass container.
Serve with pound cake, gingerbread, toast, etc. Also makes a great filling for tarts or cream puffs (add 1/2 cup whipped cream to 1 cup Lemon Curd).