Whatever you darn well please! Really, though, you're only limited by what you can bring with you and what can fit in your pots and pans. You can boil water for drinking coffee or hot cocoa. You can make eggs in a pan. You could even make stew or soup in a dutch oven. As long as you're keeping yourself safe and properly handling the food, go wild! Hey, you can always grab good marshmallow roasting sticks or a skewer to cook hot dogs over the open fire for nostalgia's sake, too.