In a large mixing bowl, combine the sliced cucumbers, halved cherry tomatoes, and thinly sliced red onion.
Add the crumbled feta cheese to the bowl with the vegetables.
In a small bowl, whisk together the olive oil, lemon juice, minced garlic, chopped dill, and chopped parsley until well combined.
Pour the dressing over the salad ingredients in the large bowl.
Gently toss everything together until evenly coated.
Season with salt and black pepper to taste, adjusting as needed.
Let the salad rest at room temperature for about 10 minutes to allow the flavors to meld.
Serve immediately, or refrigerate until ready to eat.