Muddle 3 of the lemon quarters in the bottom of a cocktail shaker (about 10 or so strong muddles).
Add mint leaves and muddle a few more times. Add the bourbon and simple
syrup.
Fill the shaker with at least six ice cubes and shake for about 15
seconds.
Strain into a glass filled with ice.
Garnish with a sprig of
mint and lemon slice.