Wash cucumbers and tomatoes under cold running water, pat dry, then slice cucumbers and dice tomatoes.

Thinly slice half a red onion.

In a large bowl, combine sliced cucumbers, diced tomatoes, and red onion.

In a small bowl, whisk extra-virgin olive oil, red wine vinegar or lemon juice, salt, and pepper.

Pour dressing over vegetable mixture and gently toss to coat.

Sprinkle with freshly chopped parsley and toss lightly to incorporate.

Let salad rest for 10–15 minutes before serving.