Avocado pureed with buttermilk (low-fat) and yogurt (with the cream on top) yields a pale green soup laced with masses of minced herbs, textured with cucumber, and garnished with slivered radishes, herbs, and green pistachios. All in all, it’s a fine soup for a hot day, and although the recipe makes just a scant quart, it will be enough for four or more servings.

INGREDIENTS

• 2 cups low-fat buttermilk
• 1 cup yogurt, preferably whole-milk
• 1 large avocado, peeled and pitted
• 1 cucumber, peeled and seeded
• 1 large garlic clove
• Sea salt and freshly ground pepper
• 3 slender scallions, white parts plus a bit of the green, finely minced
• 2 tablespoons chopped dill
• 1 tablespoon snipped chives
• 1 tablespoon minced marjoram or oregano
• 1 tablespoon minced tarragon
• 1 tablespoon chopped cilantro
• 1/2 jalapeno chile, seeded and chopped
• Zest and juice of 1 lime
• 1/2 teaspoon sweetener
• Finely sliced chives and chive blossoms
• Thinly slivered radishes
• Dill, mint, and cilantro sprigs
• 1/3 cup shelled pistachios or walnuts

 
PREPARATION
1 Puree the buttermilk, yogurt, avocado, and a quarter of the peeled cucumber in a blender until smooth, then pour it into a bowl.

2 Mash the garlic with 1⁄ 2 teaspoon salt and stir it into the puree along with the scallions, herbs, chile, and lime zest. Season to taste with salt, pepper, lime juice, and sweetener, if needed. Seed and finely dice the remaining cucumber and add to the soup. Cover and refrigerate until well chilled. Just before serving, taste and correct the seasonings.

3 Ladle the soup into bowls, then cover the surface with the chives, radishes, herb sprigs, and pistachios.