2 oz Reposado Tequila
1⁄2 oz Amer Picon (or Averna)
1⁄4 oz Crème de Cacao
1 twst Orange peel
Stir, strain, up, twist.
Clarke provides the alternative ingredients for those who don't have access to Picon (or a good replica) or Bittermens mole bitters (which were not widely available at the time).
Paul Clarke, Cocktail Chronicles
Reposado Tequila, Sweet vermouth, Amer Picon, Crème de Cacao, Bitters, Orange peel