Prepare the Patties: In a large bowl, mix together the ground beef, mayonnaise, Worcestershire sauce, and dried minced onions until well combined. Shape this mixture into 6 equal-sized patties.

Prepare the Vegetables: Clean and cut the potatoes, carrots, and onion. Place them in a large bowl. Drizzle with half of the olive oil and sprinkle with half of the Italian seasoning. Stir well. Add the remaining oil and seasoning, and stir until the vegetables are evenly coated.

Assemble the Foil Packets: Lay out 6 large squares of heavy-duty aluminum foil. Divide the seasoned vegetables evenly among the foil squares, placing them in the center. Place a beef patty on top of the vegetables in each packet.

Seal the Packets: Fold the sides of the foil over the beef and vegetables, sealing the edges tightly to form a packet. Ensure there are no openings for the juices to escape during cooking.

Cook the Packets: Preheat your grill to medium heat, approximately 325°F. Place the foil packets on the grill and cook for 20-25 minutes. Turn and gently shake the packets occasionally to prevent burning and ensure even cooking.

Check for Doneness: Carefully open one packet to check if the vegetables are tender and the beef patty has reached an internal temperature of 150°F for medium-well doneness. If not, reseal and cook for a few more minutes.

Add Cheese (Optional): If you wish to add cheese, open the packets and sprinkle the grated Colby Jack cheese over the beef patties as soon as they come off the grill. Reseal the foil to allow the cheese to melt.

Serve: Carefully open the foil packets (watch out for steam) and transfer the contents to plates. Garnish with fresh parsley if desired. Serve immediately.