Easy Lemon-Lime Mousse

Directions

1. 1
   The first step is to make the lemon curd, which you can do a day or so ahead of time, if you wish.
2. 2
   In a medium-sized heavy saucepan, using a wooden spoon, combine the butter and 1 cup of the white sugar; don't worry, it likely won't go into a smooth paste--that doesn't matter.
3. 3
   With the same spoon, stir in the eggs and egg yolks, lemon juice and lime juice (I use freshly squeezed lemon juice but have been using bottled key lime juice for the lime).
4. 4
   If the mixture looks all curdled, don't worry.
5. 5
   Place the saucepan over low heat and cook, stirring constantly, until mixture is smooth.
6. 6
   This will take about 5 minutes; as the butter melts and you keep stirring or whisking, it will come together nicely.
7. 7
   Now raise the heat to medium and cook, stirring constantly, until the mixture is thick enough to coat the back of a spoon; this will take several minutes, from as quickly as 4 mins to as long as 8 (don't let the mixture boil; if it starts to, turn heat down).
8. 8
   Remove pan from heat and stir in zest; then pour into a glass or ceramic bowl and cover with plastic wrap, letting wrap touch and cover the surface of the curd (this prevents a skin from forming).
9. 9
   Chill in fridge at least one hour; overnight is fine.
10. 10
    When ready to make the mousse, beat the cream with the remaining 1/3 cup sugar to soft (not stiff) peaks.
11. 11
    Get the lemon curd out of the fridge, peel away plastic wrap, and use a whisk to loosen up the curd.
12. 12
    Now gently fold that curd into the whipped cream, combining thoroughly--but with a light hand.
13. 13
    Spoon mousse into 6 individual dessert dishes.
14. 14
    Cover and chill for at least two hours; overnight is fine.