Beat egg yolks, milk, lime juice and lime peel in medium heavy saucepan until
blended. Cook over low heat, stirring constantly but gently, until mixture is just
thick enough to coat a metal spoon with a thin film and temperature reaches 160
degrees F, about 15 minutes. Do not allow to boil.
Remove from heat immediately.
Cool quickly: Set pan in larger pan of ice water; stir occasionally and gently
for a few minutes to hasten cooling.
Press piece of plastic wrap onto surface of
custard to prevent a "skin" from forming.
Refrigerate until thoroughly chilled,
at least 1 hour.
Spread lime custard evenly in meringue pie shell before serving.
Garnish with whipped cream, lime slices and fresh mint.
Refrigerate pie, covered, several hours or overnight, to develop full flavor
and to soften the meringue.