Peel and pit avocado; scoop into blender. Add cucumber, green onions, dill, broth, yogurt, lemon juice, cumin, salt and pepper; blend until very smooth. Cover and refrigerate until chilled, about 1 hour.
Pour into serving bowls; top with reserved green onions and dill sprigs.
Nutrients per serving: 108 calories, 5 g protein, 5 g fat (1 g saturated fat), 13 g carbohydrates (5 g sugar), 4 g fibre, 2 mg cholesterol, 370 mg sodium.
Tip: For added crunch and a pop of colour, garnish with finely chopped radishes.