Pack an Old-Fashioned glass with ice.

In a second Old-Fashioned glass place the sugar cube and add the Peychaud's Bitters to it, then crush the sugar cube.

Add the Sazerac Rye Whiskey or Buffalo Trace Bourbon to the second glass containing the Peychaud's Bitters and sugar.

Empty the ice from the first glass and coat the glass with the Herbsaint, then discard the remaining Herbsaint.

Empty the whiskey/bitters/sugar mixture from the second glass into the first glass and garnish with lemon peel.