Rinse and drain chickpeas and cannellini beans under cold water. In a large bowl, combine the chickpeas, cannellini beans, diced cucumber, halved cherry tomatoes, sliced red onion, diced bell pepper, and olives.

In a separate small bowl, whisk together olive oil, lemon juice, minced garlic, and oregano. Add salt and pepper to taste.

Pour the dressing over the bean and vegetable mixture in the large bowl. Toss everything gently for about 1 minute.

Crumble feta cheese over the top of the salad. Cover and refrigerate for at least 30 minutes.

After chilling, gently stir to recombine. Serve it in individual bowls or on a large platter.