In a cocktail shaker, add peach cubes, lemon juice and mint leaves and muddle until the peach cubes have broken up and mixed with the mint.
Add bourbon and stir.
Add ice to the shaker and shake for 15 to 20 seconds.
Strain into a highball or Collins glass filled with ice. If you’re having trouble straining it due to the pulpy peach, try a Hawthorne strainer instead.
Top with ginger beer and stir.
Garnish with a sprig of mint—gently clapped between your palms to release its scent.