1 cup sugar
1/2 teaspoon lime rinds grated or lemon rind (optional)
3/4 cup lime juice or lemon juice
Pinch salt
1 1/2 teaspoons unflavored jello
5 eggs yolk
1 teaspoon vanilla extract
2 to 3 drops food colors green
3 eggs white at room temperature
1 cup whipped cream whipped
In a small saucepan, stir 3/4 cup of the sugar, lime or lemon rind and juice, and salt. Sprinkle gelatin over top; let stand for 1 minute. Cook and stir over low heat until gelatin is dissolved. Remove from heat; set aside.
In a medium saucepan, whisk egg yolks until thick and pale yellow. Beating continually, slowly pour in gelatin mixture. Stirring over medium-low heat, cook until mixture thickens and coats a metal spoon (do not boil).
Place saucepan in a bowl which contains cold water and ice. Stir lime mixture to cool quickly and stop the cooking; when mixture reaches room temperature, remove from ice water. Stir in vanilla and food color; set aside.
In a small mixer bowl at high speed, beat egg whites until soft peaks form. Gradually add remaining 1/4 cup sugar and beat until stiff and glossy. Stir about one-fourth of the egg whites into the lime custard. Gently fold in remaining egg whites until no streaks remain. Fold in whipped cream until blended. Spoon into individual serving dishes and freeze at least 3 hours.
Remove from freezer 15 minutes before serving. Garnish with strawberries if desired.