01 - Prepare 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, avoiding overworking the meat.
03 - Divide the seasoned beef mixture into 4 equal portions and shape each into a flat patty.
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 thinly sliced potatoes in the center of each foil sheet. Layer onion slices, red bell pepper, and mushrooms evenly over the potatoes. Season the vegetables lightly with salt and pepper.
06 - Place one seasoned beef patty on top of the layered vegetables in each foil packet. Drizzle each patty with ½ tablespoon ketchup and a small amount of yellow mustard.
07 - Fold the foil tightly around each packet, crimping the edges to seal completely and prevent any juices from leaking during cooking.
08 - Place the sealed packets on a 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.
09 - Carefully open each packet, watching for hot steam. Place a slice of cheddar cheese on each patty, then reseal the packets and cook for 2 additional 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.