Tamarind Margarita

In a saucepan, simmer the tamarind and water over low heat, stirring, until the pulp dissolves. Press the mixture into a shaker through a fine-mesh sieve. Add 1/2 cup of the tequila and the sugar; shake vigorously. Add ice to the shaker, then add 1/2 cup of lime juice, the Cointreau, the orange juice and the remaining 1/2 cup of tequila; shake well.

Pour the remaining 2 tablespoons of lime juice and the salt mixture into 2 bowls. Dip the rims of 4 old-fashioned glasses first in the lime juice and then in the salt mixture. Fill the glasses with ice. Strain the drink into the glasses and garnish with the lime wedges.