Start by preheating your oven to 400°F (200°C). Take your chicken breasts and place them between two sheets of plastic wrap. Use a meat mallet or rolling pin to pound them to an even thickness of about 1 inch. Season both sides with salt and pepper.
In one shallow bowl, add the all-purpose flour. In a second bowl, crack the two large eggs and beat them until well combined. In a third bowl, combine the panko breadcrumbs, garlic powder, onion powder, and Italian seasoning.
Take each chicken breast and dredge it in the flour, shaking off any excess. Next, dip it into the beaten eggs, ensuring it is fully coated. Finally, press the chicken into the breadcrumb mixture, coating it thoroughly on both sides.
In a large skillet, heat the olive oil over medium heat. Once hot, carefully add the breaded chicken breasts. Cook for about 4-5 minutes on each side, or until they are golden brown and cooked through. Transfer the cooked chicken to a paper towel-lined plate to drain excess oil.
In an oven-safe baking dish, split the sub rolls lengthwise and place them side by side. Spoon some marinara sauce onto each roll, then place a piece of fried chicken on top. Layer 2 slices of mozzarella cheese over each chicken breast and sprinkle with grated Parmesan cheese.
Place the baking dish in the preheated oven and bake for about 10-12 minutes, or until the cheese is melted and bubbly. If you like your cheese extra golden, you can broil the subs for an additional 1-2 minutes, watching closely to avoid burning.
Once baked, remove the Chicken Parmesan Subs from the oven and garnish with freshly chopped parsley. Serve immediately with extra marinara sauce on the side for dipping. Enjoy the savory flavors and satisfying textures of this delicious sandwich!
