Rinse and drain the canned chickpeas and black beans under cold water and pat dry gently.
In a small bowl, whisk together olive oil, red wine vinegar, dried oregano, salt, and pepper until smooth.
In a large mixing bowl, combine the chickpeas and black beans.
Pour the dressing over the beans and gently toss to coat evenly.
Fold in the sliced red onion, crumbled feta, and chopped parsley. Mix until well combined.
Cover the salad and refrigerate for at least 30 minutes to allow flavors to meld.
