Classic cocktail. Rumored to have come out of the prohibition era. Some say it was created at the 21 Club in NYC.
2 oz gin (Bombay Sapphire or similar)
3/4 oz fresh squeezed lime juice
3/4 oz simple syrup
3 drops Angostura bitters
6 fresh mint leaves
Combine gin, mint, simple syrup, lime juice and bitters in a cocktail shaker with ice. Shake until the mint is well bruised. Strain into a coupe glass. Garnish with mint (slapped lightly to release oils).