1. Begin by washing your vegetables. Peel the cucumbers and slice them into 1/4 inch rounds. For the tomatoes, cut them into wedges or thick slices according to your preference. Lastly, thinly slice the red onion into rings. Place all these prepared vegetables into a large mixing bowl.

2. In a separate bowl or jar, combine the water, vinegar, olive oil, sugar, salt, black pepper, and oregano. Whisk everything together vigorously until the sugar has completely dissolved.

3. Pour the freshly made marinade over the vegetables in the bowl. Using a gentle touch, toss everything together until all the vegetables are thoroughly coated in the marinade.

4. Cover the bowl tightly with plastic wrap or a lid and refrigerate. Let the salad sit for at least 2 hours, but overnight is even better for deeper flavors.

5. When ready to serve, give the salad another gentle toss. Garnish with freshly chopped parsley and serve cold.