Combine all ingredients in a mixing glass with cracked ice and stir well. Strain into a chilled cocktail glass.
Combine all ingredients in a cocktail shaker with cracked ice and shake well. Strain into chilled cocktail glass.
Combine liquid ingredients in a cocktail shaker with cracked ice and shake well. Strain into a chilled cocktail glass and garnish with olive.
Place gin, vermouth, olives, cocktail glass, and cocktail shaker in freezer for at least 3 hours. When all components are thoroughly chilled, combine gin and vermouth in the chilled cocktail shaker and shake well. Place the two frozen olives in the chilled cocktail glass and pour the gin and vermouth mixture over it.