Place the chicken breasts on a cutting board and trim off any fat. Hold the top of the chicken breast with one hand and slice the chicken horizontally with the other hand using a sharp knife. Repeat with the remaining chicken breasts.
Place the chicken breast on top of a plastic wrap layer and cover with a second piece of plastic wrap. If you don't have plastic wrap, use parchment paper.
Pound the chicken breast to an even thickness, about 1/4 inch, using a meat mallet or the bottom of a saucepan.
Liberally season the chicken breasts with salt, pepper, garlic powder, and Italian seasoning on both sides.
Dip each chicken breast in the flour, making sure both sides are completely coated. Shake off any excess flour. Then dip the chicken breast in egg, making sure both sides are coated. Allow any excess egg to drip back into the bowl. Coat the chicken breast in panko and make sure to press the breadcrumbs onto the chicken.
Heat about 1/4 inch of oil over medium heat until the oil shimmers. Fry the chicken breasts for 2 minutes on each side or until it reaches an internal temperature of 165 degrees F.
Place the cooked chicken Milanese on a baking sheet with a wire rack and allow it to cool for 2-3 minutes. Serve with arugula and lemon wedges, if desired, and enjoy!