Combine prosecco, limoncello, lemon juice, and club soda in a punch bowl or large pitcher.
Add lemon and orange slices, and lots of ice. Stir gently to mix and chill.
Garnish with fresh mint leaves.
Ladle into glasses and serve immediately while bubbly.
Notes
Keep everything well chilled before mixing. Add extra soda water to lighten. Swap prosecco for cava or any dry sparkling wine. For more fruit flavor, toss in fresh berries.