1 1/2 lbs ripe peaches (about 5 medium), quartered and pitted (4 cups)
2 cups lowfat buttermilk, chilled
1 cup ice cubes
1/4 cup sugar, plus more to taste
1/4 tsp ground cardamom
1/8 tsp ground cumin
1/8 tsp salt
1/2 cup peach liqueur (optional)
2 tablespoons shelled unsalted pistachios, coarsely chopped
In a blender, puree peaches, buttermilk, ice cubes, sugar, cardamom, cumin, salt and liqueur, if desired, until smooth and frothy. Add sugar to taste. Divide among 4 glasses and top with pistachios. Serve immediately.