Slice cucumbers in half lengthwise, then cut into half-moons about 1/4-inch thick. Place in a colander, sprinkle with 1/2 teaspoon salt, and toss. Let sit for 10 minutes to draw out excess water. Pat dry with paper towels.
In a large bowl, combine cherry tomatoes, diced bell peppers, sliced red onion, and chopped parsley.
In a small jar or bowl, whisk together olive oil, red wine vinegar, minced garlic, dried oregano, salt, and black pepper until well combined.
Add the dried cucumbers to the bowl with the other vegetables. Pour the dressing over the salad and toss gently to coat everything evenly.
If using feta cheese, sprinkle it over the top and toss lightly. Let the salad rest for 5 minutes before serving to allow flavors to meld.