Wash and chop the cucumber, cherry tomatoes, red bell pepper, and red onion.
Add the chopped veggies to a large mixing bowl along with the kalamata olives and feta cheese.
In a small bowl, whisk together olive oil, red wine vinegar, lemon juice, minced garlic, Dijon mustard, oregano, salt, and pepper.
Pour the dressing over the salad and toss everything gently to coat.
Let the salad sit for 5 minutes to absorb the flavors.
Taste and adjust seasoning if needed.
Serve immediately or refrigerate for up to 3 days for even better flavor.
Enjoy on its own or pair it with grilled protein for a complete meal!