1-Prepare the ingredients: Slice potatoes 1/8 inch thick, thinly slice onion, and cut tomato into thick rounds.

2-Form the patties: Shape ground beef into 4 thin patties about 1/4 inch thick, pressing wider than final size.

3-Assemble the potato base: On each sheet of heavy duty foil, spread sliced potatoes and onions in a single loose layer; season lightly with salt and pepper.

4-Top with the patty: Place one beef patty on top of each potato and onion base.

5-Add condiments and tomato: Spread 1 tablespoon ketchup and 1 teaspoon mustard over each patty, then top with a thick tomato slice.

6-Seal the packets: Fold foil over ingredients and crimp edges tightly to trap steam inside.

7-Cook over the fire: Place packets over medium heat on a campfire grate or grill; cook for 12–15 minutes.

8-Flip the packets: Carefully flip each packet with tongs and cook another 12–15 minutes until potatoes are tender and beef is cooked through.

9-Add the cheese: Open packets carefully, lay a slice of cheddar cheese on each patty, reseal foil, and let sit for about 2 minutes to melt.

10-Rest and serve: Let packets rest for 5 minutes before opening to keep juices sealed in, then serve straight from the foil.