Step 1

Soften gelatin in water 5 minutes.

Step 2

Beat yolks and add 1/2 cup of the sugar, lemon juice and salt. Cook in the top of a double boiler, stirring constantly, until of custard consistency. Add grated lemon zest and softened gelatin and stir thoroughly. Cool.

Step 3

When mixture begins to get thick, In a clean bowl, whip egg whites until stiff, adding remaining 1/2 cup sugar while whipping. Fold egg whites into custard.

Step 4

Pour filling into pie shell and chill in refrigerator. Serve when firm. Garnish with sweetened whipped cream if desired.