01 - Preheat your campfire grate, 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, a generous pinch of 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 shape each into a flat, even patty roughly the width of your foil sheets.
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 a layer of thinly sliced potatoes in the center of each oiled foil sheet. Top with sliced onion, red bell pepper, and mushrooms. Season the vegetables lightly with salt and pepper.
06 - Place one seasoned beef patty on top of the layered vegetables in each packet. Drizzle each patty with ½ tablespoon of ketchup and a small amount of yellow mustard.
07 - Fold the foil edges together tightly to form 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 fully cooked through and the vegetables are fork-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 an additional 2 minutes to allow the cheese to melt.
10 - Serve the hobos directly from the foil or transfer to plates. Garnish with sliced dill pickles, chopped lettuce, fresh tomato slices, and extra ketchup or mustard as desired.