Begin by placing the chicken breasts between two sheets of plastic wrap. Using a meat mallet or rolling pin, gently pound the chicken to an even thickness of about ½ inch.
Sprinkle both sides of the chicken breasts generously with kosher salt and black pepper.
In one shallow bowl, combine the all-purpose flour and garlic powder. In a second bowl, beat the eggs until well combined. In the third bowl, mix the panko breadcrumbs with the freshly grated Parmesan cheese, finely chopped parsley, and lemon zest.
Dredge each chicken breast first in the flour mixture, shaking off any excess. Next, dip it into the beaten eggs, allowing any excess to drip off. Finally, coat the chicken in the panko mixture, pressing gently to ensure the breadcrumbs adhere well.
In a large skillet, heat the olive oil over medium-high heat. To test if the oil is ready, drop a few breadcrumbs into the oil; if they sizzle immediately, the oil is hot enough.
Carefully place the breaded chicken breasts into the hot oil. Fry for about 4-5 minutes on each side or until they are golden brown and cooked through.
Once cooked, transfer the Chicken Milanese to a plate lined with paper towels to drain any excess oil. Serve immediately with a fresh arugula salad and lemon wedges.