First, place your four chicken cutlets into a large bowl. Drizzle them with about two tablespoons of olive oil, a pinch of salt and pepper, the Italian seasoning, lemon zest, and lemon juice. Add the pressed garlic and toss everything together until the chicken is well-coated. Let it marinate for at least 20 minutes to absorb all those wonderful flavors.
While the chicken marinates, it’s time to make the pesto. Add the pine nuts, Parmesan cheese, garlic, lemon zest and juice, salt, pepper, and two tablespoons of olive oil to a food processor. Process for about 20 seconds. Add the basil and arugula, then drizzle in the remaining half cup of olive oil while processing until smooth.
Heat your grill pan over medium-high heat. Place the chicken cutlets on the grill and cook for about 3-4 minutes per side. Since they are thin, they will cook quickly. You're looking for a beautiful golden-brown color and for the chicken to be cooked through. Once done, let the chicken rest for a few minutes.
Preheat your broiler and line a baking sheet with foil. Place the rested chicken breasts on the sheet and top each one with a slice or a sprinkle of the smoked mozzarella cheese. Place the sheet under the broiler for just a couple of minutes, or until the cheese is bubbly and completely melted.
It's time for the final assembly. Cut your ciabatta loaf into four equal pieces and slice them open. Spread a generous amount of your fresh pesto on both the top and bottom halves of the bread. Place a cheesy chicken breast on the bottom piece, top it with sun-dried tomatoes and a handful of arugula, and cover with the top piece of bread.