Toast your pistachios, if desired. Place pistachios in a small pan on medium heat. Heat until you smell the pistachios. This is your indication the oils are heating up. Toss them around the pan. Watch carefully and remove as soon as you smell them or they start getting 'toasted' (light brown places on them)
Add the feta, yogurt, olive oil, lemon juice (zest & juice), and black pepper to your food processor or blender. Process the ingredients until they are smooth.
Spoon the mixture into a serving bowl and drizzle with date syrup and pistachios. I like to toast the pistachios, but you don't have to.
If you want to serve it hot you can microwave it for a few minutes or bake it for 10 to 15 minutes at 350°F (be sure to put it in an oven-safe dish).
I like to serve this dip with a mild but sturdy cracker, like Triscuit or Wheat Thins. Use your favorite. It's also good with pita and naan wedges. Vegetable sticks like celery, peppers, carrots, and cucumbers make good scoopers too.