In a large mixing bowl, combine the chickpeas, black beans, cherry tomatoes, cucumber, bell pepper, red onion, and parsley. If using feta cheese, add it to the bowl as well.
In a separate small bowl, whisk together the olive oil, red wine vinegar, dried oregano, garlic powder, salt, and pepper until well combined.
Pour the dressing over the salad mixture and toss gently to combine all ingredients thoroughly.
Taste and adjust seasoning if necessary. If you prefer a stronger flavor, add more salt, pepper, or vinegar.
Cover the salad and refrigerate for at least 30 minutes to allow the flavors to meld. Serve chilled or at room temperature.