Chop the tomatoes into wedges and place them in a large mixing bowl.
Slice the cucumbers into half-moons and add them to the bowl with the tomatoes.
Thinly slice the red onion and add it to the bowl with the other vegetables.
In a small bowl, whisk together the olive oil, red wine vinegar, minced garlic, dried oregano, salt, and pepper until well combined.
Pour the dressing over the vegetables in the large bowl.
Gently toss everything together until all the vegetables are evenly coated with the dressing.
Sprinkle the chopped parsley over the salad and give it one more gentle toss.
Let the salad sit at room temperature for 10 minutes to allow the flavors to meld before serving.
