Preheat oven to 200 degrees and prepare a baking tray. In a bowl, toss potato in half the oil, garlic powder and Italian herbs. Place in air fryer, select roast and cook at 200 degrees for 20 minutes. In a separate bowl, combine butter beans and remaining oil. Place butter beans into air fryer, select air fry and cook at 170 degrees for 10 minutes. Meanwhile, combine dressing ingredients in a small bowl. Place crispy potatoes, butter beans and remaining salad ingredients in a large bowl and drizzle with dressing.