Cook pasta according to package directions. Drain and immediately rinse under cold water until pasta is cooled.
Combine pasta, beans, celery, carrot, red pepper and onions in medium bowl.
Combine mayo, balsamic vinegar, mustard, pepper, salt & Italian seasoning in small bowl and mix well.
Pour dressing over salad and toss to coat.
Cover & refrigerate overnight (can eat immediately - but much better if let to sit overnight!).
Nutrition Info Per Serving (1/2 cup): Calories 156.3 Total Fat 3.5 g Saturated Fat 0.5 g Polyunsaturated Fat 0.3 g Monounsaturated Fat 0.2 g Cholesterol 0.9 mg Sodium 533.9 mg Potassium 171.9 mg Total Carbohydrate 26.7 g Dietary Fiber 3.8 g Sugars 1.5 g Protein 5.0 g