In a cocktail shaker muddle peaches with a muddler for about one minute.
Add alcohol and lemon juice. Bruise mint by slapping in hand to release flavour and drop into shaker. Fill shaker with ice and shake for about 20-30 secs.
Fill cocktail glass with ice* and strain shaker liquid into glass. Top with more ice and fill glass with ginger beer.
Garnish with slices of peaches and lemon and a mint sprig if desired.