Adapted from Gourmet magazine.
1/2 chilled seedless cucumber
1/3 cup firm-ripe avocado
1 scallion, chopped
1 teaspoon fresh mint leaves
1/8 cup well-shaken chilled buttermilk
1/2 cup cold water
Cut cucumber into 3 equal pieces, then coarsely chop 2 of the pieces. Chop the avocado. Blend together chopped cucumber, chopped avocado, scallions, mint leaves, buttermilk and water in a blender until smooth, 1 to 2 minutes. Chill soup, uncovered, 15 minutes.
Cut remaining cucumber and avocado into 1/4 -inch pieces and stir into soup. Thin with additional water if desired.
Per serving: 134 calories; 8 g fat (2 g saturated fat; 54 percent calories from fat); 15 g carbohydrates; 2 mg cholesterol; 73 mg sodium; 5 g protein; 5 g fiber.