3 dashes Peychaud's bitters
2 ounces rye whiskey
Enough Herbsaint to coat a glass
Fill 1 old-fashioned glass (The kind with the heavy glass bottom that tapers wider at the top. The tapering releases the aroma of the drink nicely and the heavy bottom is good for muddling and chills nicely.) with ice and cold water. Set aside to chill.
While the first glass is chilling, place a sugar cube at the bottom of another old-fashioned glass. Douse the cube with the Peychaud bitters and a bit of water, and muddle completely. Fill the glass with ice, add the rye and stir well.
Dump out the ice and water from the first glass, add the Herbsaint, and swirl to coat the glass well. Discard any extra.
Strain the rye/Peychoud/sugar mixture into the coated glass, twist the lemon peel over the top (to release its oils) and drop it in. Serve.