Preheat oven to 400°F (200°C) and line a baking sheet with parchment paper.
In a large bowl, mix together the ground chicken, eggs, parmesan, garlic powder, Italian seasoning, salt, and black pepper until fully combined.
Transfer the mixture to the prepared baking sheet and press into a thin, even rectangle. I spread mine out to the full length of my baking sheet 15x11".
Bake for 28–32 minutes, until golden, firm, and fully cooked through.
Remove from the oven and let cool slightly before slicing.
Cut into 6 flatbread pieces and use as sandwich bread.
Build your sandwich with all the toppings you like. I like using light mayo, mustard, sliced turkey, salami, mozzarella cheese, tomato, lettuce, pickled red onions and banana peppers.