Lemon curd is a lemony thickened mixture made from eggs, lemons, sugar, unsalted butter and lemon zest. Lemon curd is well-known in the U.K. where it is served with scones at afternoon tea.
You can find this product ready-made in most well stocked grocery stores or gourmet food stores. You can also purchase it online at Amazon.com Lemon Curd
1 large lemon
3/4 cup butter
1 cup sugar
Grate the lemon so that you have 1 tablespoon (peel only, no white pith).
Then squeeze the lemon; you should have about 3 tablespoons of juice.
In a double boiler over hot, not boiling, water, or in heavy 2-quart saucepan over low heat, stir lemon juice, lemon peel, butter, and sugar until the butter melts.
In a small bowl, beat eggs slightly. Add the eggs to butter mixture and cook, stirring constantly, until mixture is very thick and coats the back of a spoon well, about 15 minutes (do not boil or mixture will curdle).
Refrigerate until you are ready to use it.