Greek Yogurt Lemon Mousse

In a small bowl, whisk together yogurt, lemon zest, lemon juice and vanilla extract. Set aside.
In a small liquid measuring cup, add ¼ cup of water and sprinkle the gelatin over the top. Let it soften and then microwave for 30 seconds. Stir to dissolve.
In the top of a double boiler over simmering water, whisk the egg whites, Truvia, and sugar until the sugar has dissolved and the liquid is nearly scalding.
Quickly remove from heat and pour the egg-white mixture into the bowl of a stand mixer or a bowl that will accommodate an electric hand mixer. Add the dissolved gelatin.
Beat the mixture with the whisk attachment of a stand mixer or with an electric mixer at high speed until egg whites form a fluffy meringue.
Add lemon-yogurt mixture and fold gently until thoroughly incorporated.
Spoon into individual serving dishes. Pour the meringue-yogurt mousse into a pastry bag or large measuring cup to make the transfer easier if you want.
Refrigerate for at least an hour and a half before serving.
When you are ready to serve, garnish with fresh berries and mint.