Combine the strawberries, mint, lime juice, sweetener of choice and water in a blender. Puree until the liquid is blended and smooth. Chill the mixture for a couple of hours or so. When your ready to serve, fill 4 glasses with the puree until about 3/4 way up the glass. Top off the glasses with sparkling water or club soda. Garnish with mint leaves and strawberries. Taste and add more sweetener or lime juice, if needed. Enjoy!