1. Place the pistachios in a medium skillet and cook over moderate heat for about 5 minutes, tossing frequently, until fragrant and very lightly toasted. Remove from the heat and let cool. (The pistachios can be toasted several days in advance and stored in an airtight container at room temperature.)
2. In a medium bowl, mix together the yogurt and 4 tablespoons (or 1/4 cup) of the honey until smooth. Set aside. (Refrigerate and cover if making more than 1 hour before serving.)
3. Preheat the grill to medium heat. Place a clean grill rack or basket on the grill and let it get hot, about 3 minutes.
4. Brush the skin side of the nectarines with some of the remaining honey. Place on the hot grill, skin side down, and cook for 2 minutes. Turn and spoon about 1/2 tsp. of the honey into the pit cavity of each nectarine half. Cover the grill and cook another 3 minutes. The honey should caramelize the nectarines and they should turn a pale golden brown. The nectarines should be slightly soft but not mushy.
5. Remove from the heat and place the nectarines on a serving plate flesh side up. Spoon the honeyed yogurt into the cavity of each nectarine and top with the toasted pistachios and a drizzle of the remaining honey. Serve immediately.
Source: fresh Magazine May, June 2010