Cut each chicken breast in half, length-wise, so that you have 4 thinner pieces. Season each piece with salt and pepper and set aside.
Place your flour, beaten egg, and breadcrumbs in three separate, shallow dishes in an assembly line fashion. Flour, then egg, then breadcrumbs.
Heat the olive oil in a large skillet over medium-high heat.
Dredge each of the chicken pieces in the flour, shaking off any excess, then in the egg, and finally in the breadcrumbs, making sure to coat each side well. Place carefully into the pan and cook for 3-4 minutes, until nicely browned, then flip and cook another 3-4 minutes or until cooked through.
Meanwhile, preheat your oven broiler. Once the chicken is cooked, top with ¼ cup of marinara sauce and a slice of mozzarella. Place under the broiler for just a minute or so, to help the cheese melt.*Alternately, if your skillet has a lid, you can place the lid on for a minute and skip the oven step.
While the cheese is getting nice and melty, toast your rolls and smear some mayo or Miracle whip on either side.
When the cheese is good and melty, sprinkle some basil on top and use a spatula to place each piece of chicken on a prepared roll, top it off and devour to your little heart's content!