Whisk together vinegar, mustard, salt and pepper.  While whisking, add oil in a thin stream until blended.  Set aside.



Heat  a medium-size pot of water to boiling.  Add grean beans and cook 4 minutes or until crisp-tender.  Drain and rinse with cold water.



Tear basil into bite-size pieces.  In large salad bowl, toss basil, green beans, tomatoaes, mozzarella and kidney and white beans.  Whisk dressing, then drizzle over salad.  Toss gendly to coat and serve.