Half the number of chicken breasts as number of servings desired
2 Tbsp oil
Heat oil in a large skillet. Slice chicken breasts horizontally (be careful!) so each is half the thickness it was. Break egg into a bowl & scramble. Spread breadcrumbs on a plate. Coat chicken with egg, then press both sides of each piece into breadcrumbs to coat.
Fry chicken on each side until nicely browned & cooked through (just a couple minutes per side). put pieces in a warm oven while the rest are cooking. When ready to serve, top each piece with the tomato sauce, mozzarella, and Parmesan and melt the cheese in the oven. Serve over spaghetti & sauce.