In a large mixing bowl, combine the kidney beans, chickpeas, and green beans.

Add the chopped bell pepper, red onion, and celery to the bowl with the beans.

In a separate bowl, whisk together the olive oil, apple cider vinegar, Dijon mustard, honey, salt, and black pepper.

Pour the dressing over the bean and vegetable mixture and toss to combine. Serve immediately or chill in the refrigerator for 30 minutes before serving.