In a large mixing bowl, combine the rinsed chickpeas and cannellini beans with the halved cherry tomatoes, diced cucumber, finely chopped red onion, diced bell pepper, and Kalamata olives. Mix gently to combine.

In a small bowl, whisk together the olive oil, red wine vinegar (or lemon juice), and minced garlic until combined. Add oregano, salt, and pepper to taste.

Drizzle the dressing over the bean and vegetable mixture in the larger bowl. Toss gently to coat all ingredients.

Sprinkle the freshly chopped parsley and crumbled feta cheese over the salad and mix gently.

Cover the salad with plastic wrap or transfer to an airtight container and refrigerate for at least 30 minutes.

Serve the salad chilled or at room temperature, giving it a gentle stir before serving.