Cucumbers and radishes are a good pair, each offering distinctive texture, flavor, and color.
Put cucumber, radish, and lemon zest in a medium bowl, and add cheese.
Whisk together lemon juice, vinegar, dill, sugar, and garlic in another medium bowl, whisking until sugar has dissolved; season with salt and pepper. Whisk in the oil in a slow, steady stream until emulsified.
Add vinaigrette to cucumber mixture; toss well. Garnish with dill. Discard garlic clove before serving.
Refrigerate salad in an airtight container up to 1 hour.