In a high speed blender or food processer, combine the sliced strawberries with the granulated sweetener until smooth.
In a mixing bowl, add the heavy cream and beat very well, until stiff peaks form. Gently fold through the pureed strawberry mixture until combined.
Distribute the strawberry mousse mixture amongst 6 small glasses or ramekins. Refrigerate for at least 2 hours, to firm up.
TO STORE: Strawberry mousse should be stored in the refrigerator, covered. TO FREEZE: Place the mousse in a sealable container (or individual containers) and store them in the freezer for up to 6 months.