Meanwhile, assemble your sandwich. Butter one side of each piece of bread. Alternatively, you can spray your pie iron directly with oil. Spread the non-buttered side of one piece of bread with pesto. Layer on turkey slices and cheese. Top with the second slice of bread, with the buttered side facing the outside of the sandwich.
Place the sandwich into the preheated pie iron, sealing it closed. If the sandwich is too big for the pie iron, don’t worry about it. Just press it closed, letting the excess sandwich pieces fall out.
Cook over a campfire, rotating the pie iron often. After a couple of minutes, open the pie iron to check to see if it’s done. When the bread is golden brown and the cheese is melted. your sandwich is done.
