Lemon Jelly Filling
1/2 cup butter or margarine
2 lemons, juice and rind, about 1/2 cup
2 cups granulated sugar
2 tablespoon all-purpose flour
4 egg yolks
Combine butter, lemon juice, rind, sugar, flower and egg yolks in a double boiler. Stirring constantly, cook over medium heat until it is the consistency of custard. Remove from heat and cool to room temperature, without stirring.
Refrigerate in an airtight container.