Lemon Curd

Combine ingredients in the top of a double boiler, or use an earthenware bowl placed over (but not touching) simmering water. Cook, stirring, until mixture thickens and coats the back of a spoon, 6 or 7 minutes. Pour through a fine mesh strainer into a sterilized glass jar. Cover airtight and refrigerate when cold (mixture will thicken as it cools). Use within 4 weeks. Makes approximately 1 cup.