Named for The Boulevardier magazine, this Prohibition-era cocktail was a favorite among American expatriates living in Paris.
Combine bourbon, Campari, and vermouth in a cocktail shaker. Fill with ice and shake vigorously until outside of shaker is frosty, about 20 seconds. Strain into a chilled cocktail glass or coupe or a rocks glass filled with fresh ice. Garnish with lemon twist. (To age: Place drink in aging kit up to 2 months.)
2 ounces bourbon
1 ounce Campari
1 ounce sweet vermouth (preferably Antica Formula)
Lemon twist (for garnish)