In a blender, mix Dijon mustard, 1/2 cup extra virgin olive oil and 6 tablespoons red wine vinegar until smooth. Remove and stir in chopped chives and set aside. Brush swordfish steaks with barbecue sauce and season with salt and pepper. Cook 3 minutes on first side and flip over. Spoon 1 ounce barbecue sauce over each steak and finish cooking without turning about 4 more minutes. Meanwhile, divide cucumber salad among 4 plates. When swordfish is finished, lean one steak on each plate over salad. Drizzle with chive sauce and serve.