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