Preheat your oven to 350°F (180°C), or 160°C if you have a fan oven.
Season the chicken with salt and pepper from all sides.
Set up a dredging station: To a shallow bowl, add flour, in a second bowl whisk an egg, and in a third bowl combine panko with romano cheese, parsley, lemon zest, salt and pepper.
Dip each chicken cutlet in the flour, shaking off the excess. Dip it into the egg wash. Press it into the Romano-panko mixture, making sure it's well-coated on both sides. Repeat with the remaining cutlets.
Heat half of the oil in a large skillet over medium heat. Once the oil is hot, add 2 of coated chicken breasts (or as many as you can fit in the pan) and cook for about 3-4 minutes per side, or until the coating is golden brown. The chicken does not need to be cooked all the way through.
Wipe the skillet clean with a paper towel if there are burnt panko breadcrumbs, then add the remaining oil and repeat with the remaining chicken cutlets.
Move the chicken breasts to a rimmed baking sheet lined with parchment paper.
Pile shredded mozzarella cheese on top of each chicken cutlet.
Put the baking sheet in the preheated oven and bake for about 8-10 minutes, or until the chicken's internal temperature reaches 165°F (74°C).
Take the chicken out of the oven and top with a slice of lemon if desired, and sprinkle with fresh parsley or basil.