1/4 cup fresh blueberries
1 ounce (2 tablespoons) fresh lime juice
4 ounces (1/2 cup) reposado or añejo tequila
1 1/2 ounces (3 tablespoons) Simple Syrup
Few dashes orange bitters
Kosher or sea salt for rimming the glass
Rub the rim of two rocks or margarita glasses with a lime wedge. Swirl the rims through a small pile of kosher or sea salt to salt them. Add ice cubes to the glasses.
In a cocktail shaker muddle the blueberries and lime juice until the blueberries are pulverized. Add the tequila, Simple Syrup, bitters and a handful of ice to the shaker. Add a left over rind or two from the limes. Shake vigorously for 15 seconds, and then strain into the salted glasses.