01 - Preheat your campfire, grill, or oven to medium-high heat (approximately 400°F).
02 - In a mixing bowl, combine the ground beef with garlic powder, onion powder, smoked paprika, salt, and pepper. Mix gently just until evenly combined, being careful not to overwork the meat.
03 - Divide the seasoned beef mixture into 4 equal portions.
04 - Tear 4 large sheets of heavy-duty aluminum foil (approximately 12 inches per side) and brush the centers with olive oil to prevent sticking.
05 - Arrange potato slices in the center of each foil sheet, then layer with onion, bell pepper, and mushrooms. Season the vegetables lightly with salt and pepper.
06 - Shape each portion of seasoned ground beef into a flat patty and place on top of the vegetable layer in each packet.
07 - Drizzle ½ tablespoon of ketchup and a small amount of mustard over each patty.
08 - Fold the foil up to form tightly sealed packets, ensuring all edges are securely closed to prevent juices from leaking during cooking.
09 - Place the sealed packets on the campfire grate, grill, or in the oven. Cook for 20 to 25 minutes, flipping once halfway through, until the beef is cooked through and the vegetables are tender.
10 - Carefully open each packet, watching for hot steam. Place a slice of cheddar cheese on each patty, then reseal the packets for 2 more minutes to allow the cheese to melt.
11 - Serve directly from the packets or transfer to plates. Garnish with pickles, lettuce, tomato, and additional condiments as desired.