- In a heavy saucepan, thoroughly mix gelatin, ¾ cup sugar, and salt.
- Stir in avocado puree, lime juice, and egg yolks.
- Cook over medium heat, stirring until gelatin is dissolved, about 10 minutes.
- Chill mixture, stirring occasionally, until mixture mounds slightly when dropped from a spoon.
- When gelatin mixture is ready, beat egg whites until stiff but not dry; beat in sugar.
- Lightly stir 1 cup egg white into gelatin mixture to lighten;.
- Fold gelatin mixture into egg whites until thoroughly incorporated.
- Pour into baked pie shell; chill until firm.
- Serve topped with whipped cream, if desired.