Endive and Avocado with Tomatillo-Basil Dressing

Difficult-to-identify flavors make this bright-green dressing a pleasing surprise: lemony, herbal, fruity, with a slight bite. Although the sauce neatly coats bittersweet endive and suave avocado, it enhances other foods as well—poached and chilled fish, cooked vegetables, or poultry. The dressing yield is 1 generous cup, or enough for four servings.