1. In a small bowl, mix the Greek yogurt and goat cheese. The consistency will be fairly thick, like paste.
2. Slice one side of each dates in half lengthwise.
3. Cut the corner off a plastic bag and fill with the goat cheese mixture. Pipe the mixture into the dates.
4. Sprinkle with chopped pistachios immediately before serving.

Tip: The dates can be made and stuffed the night before. Save the pistachios until right before serving as they will get soggy!