1. Toss arugula with 2 tablespoons dressing. Divide among four plates.
2. Heat oil in a large nonstick skillet over medium-high heat. Add shrimp, sprinkle with black pepper and cook, stirring occasionally, until bright pink, 2 to 3 minutes. Stir in beans, bell pepper, celery and remaining dressing and continue cooking until shrimp are just cooked through, 1 to 2 minutes more. Stir in parsley, remove from heat and serve over arugula.