First, make a simple syrup. In a small saucepan add sugar and pour 1 cup of water. Bring to a boil and cook until sugar is fully diluted. Set aside and let it cool.
In a blender add cooled simple syrup, lemon juice, strawberries, water, and ice cubes and blend until fully incorporated.
Pour mixture into a freezer container and freeze for at least 6-8 hours.
When you are ready to serve, remove from freezer and let stand at room temperature 1 hour before serving.
Divide into cups, pour a little bit of water or carbonated water, and garnish with fresh strawberry and a slice of lemon.