Place a can of frozen limeade concentrate in the pitcher and stir it into the soda.
If you are using fresh berries, muddle half of them in the drink. Frozen berries go in at the end.
Pour the champagne in the pitcher and stir everything together.
Add the rest of the fresh berries or all of the frozen berries. Add sliced limes to the pitcher. Garnish with mint sprigs if desired. Serve immediately.
Notes
Most champagne, prosecco or sparkling wine will work. I would choose a sweeter champagne that pairs well with fruit.
You want to make this drink right before or even during parties. If you make the drink ahead of time it will lose its fizz.
Make sure to chill your champagne before adding to this drink.