2 oz. Don Julio Reposado Tequila, 1/4 oz. Dry Sack Medium Dry Sherry, 1/2 oz. Grand Marnier, 3/4 oz. fresh lemon juice, 1/4 oz. Agave nectar, 1 barspoon Blood Orange Bitters. Begin by chilling a medium sized cocktail glass. Then, in a tall mixing glass add all ingredients: bitters, agave nectar, lemon juice, Grand Marnier, Sherry and Don Julio Reposado. Fill mixing glass with ice and shake vigorously. Strain mixture into cocktail glass and garnish with a wide twist of lemon zesting the oil over the drink and rimming the glass before floating twist.