1. Stir all ingredients (except rosemary oil) in a mixing glass filled 3/4 full of quality ice. Once chilled and diluted, strain into a chilled cocktail glass with a single, dense (preferably spherical) piece of ice.
  2. Garnish with 3 drops of rosemary oil, creating a drizzle effect.
  3. Glassware: Skyscraper coupette