01 - Preheat grill to medium-high heat, approximately 400°F.
02 - In a large mixing bowl, combine cut potatoes, olive oil, rosemary, thyme, parsley, garlic, salt, and pepper. Toss thoroughly until all pieces are evenly coated.
03 - Cut two large sheets of heavy-duty aluminum foil. Evenly divide the potato mixture between the sheets and arrange in a single layer. Fold the foil over the potatoes and tightly crimp the edges to seal, creating two sealed packets.
04 - Place foil packets directly onto the grill grates. Grill for 20 to 25 minutes, turning once midway, until potatoes are fork-tender and lightly browned.
05 - Carefully open the foil packets, avoiding hot steam. If desired, sprinkle with grated Parmesan and additional fresh herbs before serving. Serve hot.