These can also be made with with key lime juice and served on a graham cracker crust.
6 egg yolks
1 cup sugar
1/4 cup fresh lemon juice (or key lime juice)
1 3/4 cups heavy cream
Whisk together yolks, sugar, lemon juice, and salt. Set bowl over a pot of simmering water. Whisk until mixture has thicked. Place over ice water bath to cool. Whip cream until soft peaks. Fold cream into lemon mixture. Pour into small molds or ramekens. Freeze.
I serve mine with berries and an orange reduction.