In an electric mixer, using the whisk attachment, beat the egg whites on medium speed. As the egg whites start to foam, gradually add the sugar while increasing the whisking speed. Whip until the egg whites become soft peaks. Transfer the whipped egg whites to a medium bowl and set aside.

Pour the whipping cream into the electric mixer bowl, and using the whisk attachment, whip until soft peaks form.

Fold the lemon zest into the whipped egg whites, then gently fold the whipped cream.

Spoon the mixture into four 1-cup Mason jars (250 mL) and place in the freezer for 2 hours. Top with berries or whipped cream before serving.

For a twist, substitute the lemon zest with 2 teaspoons (10 mL) of ground coriander; unusual, but refreshingly delicious.