Rinse the chicken breast fillets and drain. In a bowl, whisk together the egg and milk with salt and pepper. In a separate bowl, place the breadcrumbs.

Dip each chicken breast into the egg mixture, then coat with breadcrumbs, pressing gently. Heat oil in a frying pan over medium-high heat. Cook chicken for 5 minutes per side until golden and crispy.

Transfer the fried chicken to a baking dish. Top with tomato sauce and grated mozzarella cheese. Broil in the oven until cheese is bubbly and golden. Serve with spaghetti.