I've been cooking in foil packages for years! Great way to make a whole meal. Cut up sweet potatoes, white potatoes, and whatever veggies you like. I don't mix raw meat and veggies except for skewers, which make great foil package meals. Set packages either on a grate over coals, over a gas flame, buried in campfire coals....
When I was a teenager I liked to take a tomato, hollow it out and stuff it with cheese and if there was wild garlic available or chives, add that. Maybe a chunk of ham if there was one. Wrap it in foil, bury it in the coals from breakfast, cover it with ash, and go for a hike. In the evening, dinner is ready!
One day at Jenny Springs in the Monongahela National Forest, I came home to camp exhausted from a good day's hiking, starving and anticipating my stuffed 'mater, and found an enormously obese raccoon sitting in the spring chowing down on my dinner! The coals had cooled down enough that he wasn't deterred from digging it up. After that I carried enough tin foil that I could make a cover over the coal-hole.
You can also use a large tin can the same way. You have to use pliers to pull it out of the coals. A bit harder for raccoons, but not impossible.
The Dire Wolfess