This is my spin off from a couple favorite cocktails of mine, the "Moscow" and "Kentucky" mules. When we ran out of bourbon, we made due with Irish whiskey to great success.
2 parts Jameson Irish whiskey
4 parts Ginger beer
Several dashes of citrus aromatic bitters
Add whiskey and ginger beer to shaker over ice. Shake, relieve pressure, continue shaking until cold. Strain into shilled glass with ice, and add bitters and stir. No garnish necessary, but lime or orange peel/twist recommended.