In a cocktail shaker, muddle fresh mint leaves and ginger (if using fresh ginger). Add remaining ingredients, including ice. Cover shaker tightly, pick it up and turn it sideways, a full 90 degrees. Hold the shaker with both hands (one on each piece) and shake vigorously in a horizontal motion for 12-15 seconds. Remove shaker cap and strain into a glass of fresh crushed ice. Suggested Garnish: Fresh Mint Sprig