In a saucepan, combine 1 cup of the milk, 1/4 cup of the sugar, 1/4 cup of the nuts, the salt and the vanilla; scald.
Mix the remaining 1/3 cup milk with 1 whole egg and cornstarch.
Thoroughly stir some of hot mixture into egg mixture (adding a small amount first to even out the temperature helps to prevent the egg from scrambling when added to the rest of the hot mixture); return all to saucepan.
Cook 5 more minutes, stirring constantly, until mixture thickens.
Cool 1 hour.
Beat egg whites until soft peaks form; fold carefully into cooled mixture.
Pour into pie shell; chill.
Before serving, top with sweetened whipped cream and remaining 1/4 cup nuts.