1 1/2 ounces dry vermouth
3/4 ounce bourbon whiskey
3/4 ounce Benedictine
1 dash peach bitters
Shake with ice and strain into a chilled cocktail glass.
Source: The Café Royal Cocktail Book (1937), by W. J. Tarling
A nice twist on a Manhattan style of cocktail. It uses dry vermouth instead of sweet, but the Benedictine provides the difference, along with some interesting extra character.