01 - Preheat your grill to medium-high heat, approximately 400°F. Allow the grates to fully heat for even cooking.
02 - In a large mixing bowl, combine the cut potatoes with olive oil, rosemary, thyme, parsley, minced garlic, kosher salt, and black pepper. Toss thoroughly until every piece is evenly coated with the herb and oil mixture.
03 - Tear two large sheets of heavy-duty aluminum foil. Divide the seasoned potato mixture evenly between the two sheets, spreading each portion into a single even layer. Fold the foil over the potatoes and tightly crimp all edges to seal, creating two secure sealed packets.
04 - Place the foil packets directly onto the grill grates. Grill for 20 to 25 minutes, flipping the packets once halfway through the cooking time, until the potatoes are fork-tender and lightly golden browned on the edges.
05 - Carefully open the foil packets, watching for hot escaping steam. Sprinkle with grated Parmesan cheese and additional fresh herbs if desired. Serve immediately while hot.