In a shaker ¾ full of ice add tequila, Agua de Jamaica, lime juice, and agave nectar. Shake vigorously until very cold. Strain into an old fashioned glass filled with ice.
For the Agua de Jamaica
In a small saucepan bring 1 cup of water to a boil and remove from heat, add hibiscus flowers, cover and allow to steep for about 10 minutes. Strain and pour into a clean jar. Store in the fridge for up to 1 week.