The Boulevardier is a variant of the cocktail known as the Negroni, itself a ginned-up twist on the Americano, or what Americans living in Italy used to call it when they added sparkling water to their Milano-Torino, a classic Italian aperitivo composed of bitter Campari from Milano, and sweet Martini & Rossi vermouth from Torino.
They say the Negroni was invented by an Italian count who opted to nix the fizz and add some gin to the mix. This brings us to the Boulevardier, which was reputedly invented by an American expat and publisher of a Parisian literary magazine of the same name.
The Boulevardier is simply a Negroni with Bourbon in the place of gin.
1 1/2 oz. bourbon
1 oz. Campari
1 oz. sweet vermouth
*In French, a Boulevardier is a French term for someone who can be seen on all the most fashionable boulevards. A “man about town”, so to speak.