2    Egg yolks
3/4 c  Sugar
3 tb Butter
1 ts Lemon rind,grated
2 tb Lemon juice
1 1/2 tb Cornstarch
3 tb Water

Combine egg yolks, sugar, butter rind, and lemon juice in top half of a
double boiler. Cook over simmering water until quite thick, then cool
slightly. Mix cornstarch with water and stir into lemon mixture. Cool
before spreading on cheese cakes.