Slice and Dice: Thinly slice the cucumber, dice the tomatoes, and thinly slice the red onion. If desired, mince the garlic for a subtle, added flavor.
Combine in a Bowl: Place the cucumber, tomatoes, red onion, garlic (if using), chopped parsley, and dill in a large mixing bowl.
Make the Dressing: In a separate small bowl, whisk together the sour cream (or Greek yogurt), freshly squeezed lemon juice, salt, and black pepper until smooth and well combined.
Toss the Salad: Pour the dressing over the cucumber, tomato, and onion mixture. Toss gently to ensure all ingredients are evenly coated with the creamy dressing.
Serve: Transfer the salad to a serving bowl. For the best flavor, serve immediately or refrigerate for up to 1 hour before serving to let the flavors meld.