1In a small bowl, Mix olive oil, vinegar, water, sugar,
dry mustard, salt and pepper and cayenne pepper if using. Whisk thoroughly and set aside.
2Place green pepper, carrot, celery, and red onion in a large mixing bowl and toss to mix. Set aside.
3One can at a time, empty each can of beans into a colander and rinse well to wash off the can juices. Add to fresh vegetable mixture.
4Gently mix vegetables and beans together, then whisk dressing one more time and pour over veggies and beans. Mix gently but thoroughly. Cover bowl and refrigerate overnight or make early on day of serving. You want the dressing to season the vegetables and beans. Taste before serving to adjust salt and pepper if needed.