In a colander, drain and rinse 1 (16-ounce) canned dark kidney beans and 1 (16-ounce) canned garbanzo beans in cold water. Transfer the drained beans to a large bowl. Add 1 (12-ounce) bag frozen cut green beans and ½ medium diced red onion.
In a small bowl, whisk ⅓ cup white wine vinegar, 2 tablespoons apple cider vinegar, 2 tablespoons granulated sugar, and 2 tablespoons olive oil.
Pour the dressing over the bean mixture and toss until coated. Season with salt and pepper to taste. Cover and refrigerate for 20 minutes before serving to let the beans marinate in the dressing.
Video
Notes
Storage: Store in an airtight container in the fridge for 4–5 days. It’s even better made ahead, just give it a good stir before serving to redistribute the dressing.