Preheat a grill pan or grill to medium heat. Cut the peaches in half and remove the pits. Brush the cut sides with a little olive oil, then grill them, cut side down, for 3 or 4 minutes.

Stir the pistachios and honey together to make a paste. Stir in a little minced mint. Top the warm peaches with the pistachio-honey-mint paste.