Begin by placing chicken breast fillets between two sheets of plastic wrap. Using a meat mallet, gently pound the chicken until it's about 1/2-inch thick. Once finished, pat the chicken dry with paper towels and set aside.

In a large mixing bowl, combine freshly made breadcrumbs with finely grated Parmesan, lemon zest, chopped flat-leaf parsley, and a pinch of black pepper. Stir until well blended.

In a separate bowl, whisk together the beaten egg and milk until smooth.

Dust each chicken fillet lightly with plain flour, dip into the egg wash to coat, then transfer to the breadcrumb mixture, pressing down gently.

While the schnitzels chill, prepare the coleslaw by combining finely shredded savoy cabbage, grated carrot, and diced red onion in a large bowl. Drizzle in mayonnaise and mix well.

Heat olive oil in a frying pan over medium heat. Fry the chilled schnitzels for 4 to 5 minutes on each side until golden brown and cooked through.

Serve the schnitzels alongside the coleslaw, garnished with lemon wedges.