Mix milk, salt and juice until blended and thickened.
Add pineapple, well drained, and 2 or 3 drops green colouring, and mix well.
Pour this filling into the cooled pie-shell and chill for 2 — 3 hours.
Whip a cup of heavy cream until stiff, fold in 1 tblspn, icing sugar and 1/2-tspn.
vanilla essence, and spread on top of pie.