Sparkling Cherry Rhubarb Lemonade

Bring the rhubarb, sugar and water to a boil. Simmer 5-10 minutes. Strain the mixture and discard the solids. Add the frozen lemonade and the juice from one fresh lemon; chill until cold.

When ready to serve add the soda. (You can add more water/soda depending on how tart/sweet you like it.)
Slice the remaining lemon for serving. Pour lemonade over ice and add lemon slices.