1 1/2 oz of Light Rum
2 tsp of green creme de menthe (or Mint liqueur)
1 tsp of Triple Sec
1 tsp of Lime Juice
1 tsp of sugar
1 slice of lime
Combine everything but the lime slice in a cocktail shaker with ice. Shake well and strain into a cocktail glass. Garnish with a slice of lime.