Step 1: Preheat your oven to 400°F (200°C), or prepare your grill/campfire for medium-high heat. Tear off four large sheets of heavy-duty aluminum foil (about 18x18 inches each). Spray the center of each sheet generously with cooking spray.
Step 2: In a large bowl, combine the ground beef, salt, black pepper, paprika, and onion powder. Mix gently until just combined (do not overmix). Divide the seasoned ground beef into four equal patties.
Step 3: Place one seasoned beef patty in the center of each prepared foil sheet. Arrange a quarter of the sliced potatoes, onions, carrots, and minced garlic around and on top of each beef patty. Drizzle each packet with 1/2 tablespoon of olive oil.
Step 4: Bring the long sides of the foil together over the ingredients and fold them down tightly to seal. Then, fold and crimp the short ends to create a secure, airtight packet.
Step 5: Place the foil packets directly on the oven rack, grill grates, or hot coals. Cook for 30-40 minutes, or until the potatoes are tender and the ground beef is cooked through (internal temperature of 160°F/71°C). Cooking time may vary depending on method and thickness of ingredients. Carefully check one packet for doneness.
Step 6: Carefully open the foil packets (watch out for steam!) and check for doneness. If desired, sprinkle with fresh parsley or shredded cheese before serving. Serve hot directly from the packets for easy cleanup.