Frozen Lime Cream

Directions

1. 1
   Whisk flour, sugar and yolks in medium bowl to blend.
2. 2
   Bring milk to simmer in heavy medium saucepan.
3. 3
   Gradually whisk hot milk into yolk mixture.
4. 4
   Return mixture to same saucepan.
5. 5
   Whisk over medium heat until pastry cream thickens and simmers, about 5 minutes.
6. 6
   Remove from heat.
7. 7
   Whisk in lime juice and peel.
8. 8
   Cool.
9. 9
   Combine 1/2 cup sugar and water in heavy small saucepan.
10. 10
    Stir over low heat until sugar dissolves.
11. 11
    Increase heat; boil until thermometer inserted into mixture registers 240F., tilting pan to submerge bulb, about 5 minutes.
12. 12
    Meanwhile, beat egg whites in large bowl until soft peaks form.
13. 13
    Add 2 tablespoons sugar; beat until stiff but not dry.
14. 14
    Slowly pour boiling syrup into whites, beating until cool, about 5 minutes.
15. 15
    Whisk 1/4 of meringue into pastry cream.
16. 16
    Fold in remaining meringue.
17. 17
    Freeze lime cream until firm, about 8 hours.
18. 18
    (Can be made 2 days ahead.)