Creating this Mediterranean Salad with Cucumber, Tomato, and Onion is simple if you follow these steps:

1. Prepare the Vegetables: Begin by dicing the cucumbers and tomatoes. Thinly slice the red onion and set aside.
2. Combine Ingredients: In a large mixing bowl, add the diced cucumbers, tomatoes, and sliced onions. If using, add the Kalamata olives and feta cheese.
3. Make the Dressing: In a separate bowl, whisk together the olive oil, red wine vinegar, dried oregano, salt, and pepper until well combined.
4. Dress the Salad: Pour the dressing over the salad mixture. Gently toss to combine, ensuring all ingredients are well coated.
5. Chill (Optional): For enhanced flavor, let the salad chill in the refrigerator for about 10 minutes before serving. This allows the flavors to meld.
6. Garnish and Serve: Just before serving, sprinkle fresh parsley on top for a pop of color and added freshness.