Slice each chicken breast in half horizontally to create thin cutlets. Place one cutlet at a time into a resealable freezer bag and pound with a meat mallet or rolling pin until evenly flattened to a thickness of approximately ⅛ to ¼ inch (3–6 mm). Repeat with remaining chicken.

Prepare the brine by combining the water, kosher salt, and sugar in a medium bowl, stirring until fully dissolved. Add the flattened chicken to the brine and refrigerate for 30 to 45 minutes. Do not exceed this time to prevent over-salting.

Remove the chicken from the brine and pat thoroughly dry with paper towels.

In a shallow bowl, combine the panko breadcrumbs, black pepper, fine salt, garlic powder, paprika, and sesame seeds. Place the flour in a second shallow bowl. In a third bowl, beat the eggs.

Set up a breading station in the following order: flour, eggs, panko mixture. Dredge each piece of chicken in flour, shaking off excess, then dip into the beaten eggs, and finally coat evenly in the panko mixture, pressing gently to adhere.

Line a 13 × 18-inch (33 × 46 cm) baking sheet with paper towels and set aside.

Heat approximately ⅛ inch (3 mm) of vegetable oil in a large nonstick skillet over medium heat until hot and shimmering. Fry the chicken in batches, cooking each piece for 2 to 3 minutes per side, or until golden brown and cooked through. Adjust heat as needed to prevent over-browning.

Transfer cooked chicken to the prepared baking sheet to drain briefly. Repeat with remaining chicken.

Serve immediately, garnished with lemon wedges if desired.