In a large heatproof bowl, soak the bulgur in the boiling water for 15 minutes or until it has absorbed the water and is soft. Stir in the spinach, beans, radishes, green onions, cucumbers and red peppers.
Combine mustard, vinegar, cheese and black pepper. Whisk in oil until well blended. Pour dressing over salad and toss to mix. Serve at room temperature or chilled.