In a large bowl, stir together all of the creamy ingredients (sour cream, cream cheese, parmesan, and half the mozzarella).
Add in the spinach and Knorr soup mix. Stir well with a wooden spoon until combined. If you’re making this at home before your trip, store it in an airtight container in your cooler.
Lay out two large sheets of aluminum foil. Spoon the cheese mixture into the center, top with reserved mozzarella, and fold it up, crimping the edges tightly.
Place the packet near the hot coals (not directly in the flames) and let it cook for about 20-25 minutes, until everything is warm and bubbly. You can also place it on a campfire grill, barbecue grill, or cook it in a cast-iron skillet if you prefer.
Carefully open the foil (watch out for steam!) and transfer the dip to a bread bowl or serve it straight from the foil with tortilla chips, pita chips, or a sliced baguette.