4 medium cucumbers (about 2 1/4 lb.), peeled, seeded, and chopped
2 cups plain white yogurt
1 cup low-sodium chicken or vegetable broth
3/4 cup sour cream
1/2 cup chopped green onions (white and pale green parts only)
1/4 cup chopped fresh dill
1-2 cloves garlic, peeled and minced
2-3 tablespoons olive oil
2 tablespoons fresh lemon or lime juice
1 teaspoon Dijon mustard
Sea or Kosher salt and black pepper
6-8 ounces shelled cooked crabmeat
In a blender or food processor, in batches if necessary, whirl the cucumbers, yogurt, broth, sour cream, green onions, dill, garlic, olive oil, lemon juice, and mustard until medium smooth. Add salt and pepper to taste.
Transfer to a bowl, cover, and chill until cold, at least 2 hours and up to 6 hours. Ladle chilled soup evenly into bowls.
Drizzle with olive oil and top each serving with about 1/4 cup crabmeat or shrimp.
Garnish with diced tomatoes, cucumbers, green onions, and avocado or sliced radishes and chopped dill.
Makes 6 cups; 4 servings.