1Combine the peeled and sliced Persian cucumbers, rinsed and drained chickpeas, crumbled feta, chopped dill, and chopped shelled pistachios in a bowl.
2In a separate bowl, whisk together the olive oil, red wine vinegar, oregano, dried mint, Dijon mustard, sumac, salt, pepper, and garlic powder to create the dressing.
3Pour the dressing over the salad ingredients and toss to combine.