Thinly slice the radishes into 1/8-inch rounds using a mandoline or sharp knife—this uniform thickness ensures even flavor absorption and a consistent texture throughout the salad. Peel the cucumbers if desired (I prefer leaving the skin on for color and nutrition), then cut them into thin half-moons or quarter-rounds roughly the same size as the radish slices. Place the prepared vegetables in a large mixing bowl and set aside.

In a separate bowl, combine the sour cream, olive oil, and lemon juice, whisking until smooth and well incorporated. Add the lemon zest, garlic powder, sugar, salt, and pepper, stirring to distribute the seasonings evenly. Finally, fold in the finely chopped fresh dill and chives—I like to add the herbs just before combining with vegetables to preserve their bright flavor and vibrant color.

Pour the creamy herb dressing from Step 2 over the sliced vegetables from Step 1 and gently toss until all the radishes and cucumbers are evenly coated. Taste and adjust seasonings if needed—the salad is best served immediately while the vegetables are crisp, though it can be refrigerated for up to 2 hours.