01 - Preheat your campfire, outdoor 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 black pepper. Mix gently just until the seasonings are evenly distributed, taking care not to overwork the meat.
03 - Divide the seasoned ground beef into 4 equal portions, shaping each into a uniform ball.
04 - Tear 4 large sheets of heavy-duty aluminum foil, approximately 12 inches per side. Brush the center of each sheet with olive oil to prevent sticking.
05 - Arrange sliced potatoes in the center of each oiled foil sheet. Layer onion slices, red bell pepper strips, and mushrooms over the potatoes. Season the vegetables lightly with salt and pepper.
06 - Flatten each portion of seasoned ground beef into a patty and place one on top of the vegetable bed in each packet. Drizzle each patty with ½ tablespoon ketchup and a small amount of yellow mustard.
07 - Fold the foil edges together to form tightly sealed packets, crimping the seams to ensure no juices escape during cooking.
08 - Place the sealed packets on the campfire grate, grill grates, 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.
09 - Carefully open each packet, watching for hot steam. Place a slice of cheddar cheese on each patty and reseal the packets. Let rest for 2 minutes until the cheese melts.
10 - Serve directly from the foil packets or transfer to plates. Garnish with sliced dill pickles, chopped lettuce, fresh tomato slices, and additional condiments as desired.