2 1/2 oz. Sazerac rye whiskey
1 to 2 teaspoons Herbsaint
1 teaspoon simple syrup (half water, half sugar)
3 to 4 dashes Peychaud bitters
1 lemon twist, for garnish
Stir all ingredients, except the garnish, together over ice and strain into a chilled cocktail glass. Add the garnish.