Prep the Chicken: Season the chicken cutlet with salt and pepper. Dredge it in flour, then dip it into the beaten egg, and coat it evenly with breadcrumbs.
Cook the Chicken: Heat a shallow layer of oil in a pan over medium heat. Fry the chicken for about 4–5 minutes per side, or until golden and fully cooked through. Transfer to a paper towel–lined plate.
Assemble the Sandwich: Spread pesto on one slice of bread. Layer 4 slices of mozzarella, followed by the crispy chicken cutlet, then the remaining 4 slices of cheese. Top with the second slice of bread.
Melt & Crisp: Bake or air fry the sandwich at 375°F (190°C) for about 8 minutes, or until the bread is golden and the cheese is fully melted.
Serve: Slice, dip in mayo (or any sauce you love), and enjoy the crispy, cheesy perfection.