Every summer when my dear friend Angie Williams comes back from Chile to visit, we all get to enjoy her Pisco Sour cocktails. Pisco is a brandy-based spirit popular in Peru and Chile that I haven’t been able to find near me. Its herbal, musky flavor reminds me of tequila; because the ingredients are similar to those in a margarita, tequila makes a fine substitute. Angie makes hers frozen in a blender—refreshing in summer and easy t