Dartmouth Highball

  1. 1 ½ oz pimm's no. 1
  2. ¾ oz gin
  3. ¾ oz simple syrup
  4. ½ oz lemon juice
  5. 4 mint leaves
  6. 2 oz ginger beer

Muddle mint and simple in shaker, dry shake all except ginger beer, and strain into ice-filled collins glass. Top with ginger beer and garnish with mint sprig.