Place the lemon peel and mint leaves into a sturdy glass. Add a small drop of elderflower syrup and gently muddle everything together. This releases the fresh citrus oils and mint aroma without overpowering the drink.

Pour in the remaining elderflower syrup, tonic water, and club soda. Stir gently to combine while keeping the bubbles lively and fresh.

Fill a serving glass with plenty of ice cubes. Pour the prepared spritz mixture over the ice for an instantly chilled drink.

Top with a fresh mint sprig for a vibrant finishing touch. Serve immediately and enjoy the refreshing sparkle.