Slices of bread (a top and bottom)
Slices of deli meat (ham, bologna, turkey, etc.)
Spinach, lettuce, etc.
Basil, rosemary, thyme, etc.
Oil (spray canola is very convenient)
Heavy duty aluminum foil
Prepare your ingredients by slicing how you would for any normal sandwich. Lay out a generous piece of tinfoil underneath your prep space.
Then take your slices of bread and spray (or spread) both sides lightly with oil. Place one slice on the aluminum foil.
Pile on your ingredients in any order you like. Just as you would a normal sandwich. Then top with the other lightly oiled slice.
Roll your sandwich snugly in the tin foil. If this is your first try, you may wish to wrap twice to prevent burning.
Toss into the coals of the fire. Not directly on the flame. Then let sit for a few minutes (about 5) and flip. You can periodically check to make sure it isn't burning.
Sandwich is done when the bread is lightly browned and contents are warm (cheese is melted). You'll be surprised by how awesome it looks!