From Liquor.com
Garnish: orange twist
Combine all ingredients into a mixing glass with ice
Stir until well-chilled
Strain into a rocks glass with a large ice cube
According to legend, this cocktail was created in 1919 when Italian Count Camillo Negroni asked a Florence bartender to add gin to his Americano. Although sweet vermouth is classic for this drink, many prefer it made with dry vermouth. Substitute bourbon for the gin and you have yourself a Boulevardier.