1) In top part of a double boiler or in a heavy saucepan, scald milk and rind over hot water.
2) Slightly whip egg yolks, just enough to mix.
3) Add in salt and sugar, stirring and then slowly mix in hot milk.
4) Immediately put the mixture back to boiler over non-boiling hot water and stir cook until the mixture is thick enough to coat a metal spoon.
5) Let cool and chill, covered.