2 oz Don Julio Blanco Tequila, 1/2 oz Grand Marnier, 1 oz fresh squeezed Kaffir lime juice, 3/4 oz fresh Mandarin Orange Juice, 1 tsp simple syrup. Pour ingredients one at a time into a tall mixing glass. Fill mixing glass with ice. Shake vigorously and strain into a pre-chilled Martini glass or strain over fresh ice into a tumbler (for "on the rocks"). Garnish with a slice of Mandarin orange.