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 black pepper. Mix gently just until the seasonings are evenly distributed, being careful not to overwork the meat.
03 - Divide the seasoned beef mixture into 4 equal portions and set aside.
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 oiled foil sheet. Layer onion slices, red bell pepper strips, and sliced mushrooms evenly 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 foil packet.
07 - Drizzle approximately 1/2 tablespoon of ketchup and a small squeeze of yellow mustard over each beef patty.
08 - Fold the foil tightly around each packet, crimping the edges firmly to create a sealed enclosure that will trap steam and prevent any juices from leaking during cooking.
09 - 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 fully cooked through and the vegetables are fork-tender.
10 - Carefully open each packet, watching for hot steam. Place a slice of cheddar cheese on each patty, then reseal the packets and let them rest for 2 minutes to allow the cheese to melt.
11 - Serve the packets directly from the foil or transfer to plates. Garnish with sliced dill pickles, chopped lettuce, fresh tomato slices, and additional condiments as desired.