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 lightly with olive oil to prevent sticking.
05 - Arrange thinly sliced potatoes in the center of each foil sheet, then layer with onion, bell pepper, and mushrooms. 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 vegetables in each foil packet.
07 - Drizzle approximately 1/2 tbsp ketchup and a small amount of yellow mustard over each patty.
08 - Fold the foil tightly to form 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 additional minutes to allow the cheese to melt.
11 - Serve directly from the foil packets or transfer to plates. Garnish with sliced pickles, chopped lettuce, tomato slices, and extra condiments as desired.