Combine the hibiscus flowers with the boiling water.
Let sit for 30 minutes.
Refrigerate if not using immediately.
To Make the Hibiscus Margarita
Combine all the ingredients in a cocktail shaker filled with ice. Shake for 30 - 45 seconds. Pour into an salt rimmed glass over ice.
To rim a glass: combine ¼ cup salt and lime zest together. Pour onto a small plate. Cut a lime wedge across the thickest part of the wedge down to the peel. Place the glass rim into the cut and run the wedge around the rim. Either dip the glass into the salt or, holding the glass parallel to the plate, rotate the glass rim on top of the salt.
Tequila - although I love using Reposado tequila in Margaritas, for this one, I prefer a silver tequila.
Hibiscus flowers - you can find hibiscus flowers at Hispanic markets, in well-stocked grocery stores and online.
Agave nectar - agave and tequila go together really well (being related and all :-)) but you can substitute simple syrup or honey if you don't have agave nectar.
Cointreau - used in the classic margarita, it adds just that little "something special" to the cocktail. You can omit or use another orange liqueur.
Rimming the Glass:
This is completely optional but if you like the look/taste, it's easy to do. Combine ¼ cup coarse salt with the grated lime zest. Place on a plate and run a wedge of lime around the rim of the glass. Carefully dip the glass into the salt.
TIP: Use a paring knife to slice the lime wedge across the widest part of the slice down to the peel. Slide the glass rim into the cut and run the wedge around the glass - this helps make the salted rim even!
The hibiscus tea can be made up to 4 days in advance stored in the refrigerator.
If you're planning to serve these at a party, you can shake them the day of the event and store in the refrigerator. Then all you need to do is give the container a brief shake and pour 3 ½ oz. over ice, garnish and serve.