In heavy 1 1/2-quart saucepan, mix sugar, lemon peel and lemon juice with wire whisk.
Stir in butter and eggs. Cook over medium heat about 8 minutes, stirring constantly, until mixture thickens and coats back of spoon (do not boil). Immediately pour into one 1-pint container or two 1-cup containers.
Store covered in refrigerator up to 2 months.